Let's cut to the chase.
1) Fragment Solo From the Rest of the SongTo save yourself the trouble of having to skip to 5:55 every time you need to learn the solo to "Stairway to Heaven," using a free online audio cutter at mp3cut.net can come in handy. You can focus all your listening attention towards the solo helping you internalize and become more familiar with the sound and feel without being distracted by other sections of the song.
2) Listen To the Solo Section RepeatedlyAfter step one is complete. Listen to the solo section repeatedly until you can flawlessly hear it from start to finish in your head without actually listening to it being played. It may sound crazy but it's the first step to fine-tuning your mind and ears to be able to pick apart the solo as accurately as possible by ear.
3) Learn the Solo by EarEver watch a YouTube cover of one guy playing a solo and think "Wow, that was smooth and effortless. [Insert guitarist] would be proud!" and another guy playing the same solo correctly and thinking "It sounded right, but something's amiss." While this is purely anecdotal, from my experience it's because the former learnt by ear and the latter learnt by tabs. I have noticed that guitarists who rely only on tabs tend to be rigid and lack feel.
Tabs cannot denote whether the guitarist was striking the strings with an angled or flat pick attack or the attitude or power he expressed in a particular passage of the solo. Only your ears can do that. Relying solely on tablature is a lazy and hindering habit that every serious guitarist must grow out of immediately.
Playing by ear has numerous benefits (plenty of articles cover this) It's what separates the masters from the amateurs. However, tabs can be useful if you find it extremely difficult to decipher a certain section. Other people's interpretations may give you some clues if you're in a tough spot. Use them as an aid but not as a preliminary tool to learn songs or solos.
4) Tools for TranscribingLook, don't throw away money on fancy transcribing software unless it offers you a lot more than your free existing options and is affordable for you. Otherwise good ol'free VLC Media Player works really well for solos I've worked out.
For those who don't know, it's got a loop function and a playback speed adjuster, which is pretty much all you need. Another free software to look into is Best Practice Music Software. It's greatest feature is the pitch adjuster which saves you the trouble of de-tuning and re-tuning when trying to work out solo's written by Van Halen, Hendrix or Slash who are tuned down a 1/2 step.
5) Transcribe UnpluggedUse a good pair of headphones. Place only one headphone in your ear and leave the other one free. Make sure your guitar is unplugged. This ensures the cleanest possible sound making it easier to transcribe what you hear.
6) Baby StepsThe average duration of a solo ranges between 1-2 mins give or take. Focus on looping out small section until you get to then end. If it's difficult to decipher, slow it down (e.g. - Loop the audio from 0:00-0:10 and reduce the playback speed to 0.72x decipher the piece on using your ears and your guitar and continue).
7) Eliminate DistractionsTranscribing accurately requires a lot of concentration. Get rid of any obvious distractions. Another not so obvious distraction is jumping from one solo to the next without properly finishing either one. The end result is being almost there but not quite. You don't want that. Finish what you start then move on.
8) It Will Never Sound Exactly The SameIt's a futile effort to match the guitarist behind the solo, regardless of how easy or difficult the solo is. You do not have his brain, fingers, precise amp and effects settings, guitar setup, studio environment etc.
These factors all come together to create the sound he has. Sometimes certain sections are damn near impossible to decipher which will require some improvisation on your part.
The point is, accept that your interpretation is going to sound slightly different but don't fight it, look to play within your style. Your vibrato may not sound like Jimmy Page's but who cares? You're not Jimmy Page. Play how you play.
9) Get a Second OpinionWhen you keep working on a piece, it's easy to miss certain notes due to fatigue and loss of concentration. A fresh pair of ears can sometimes detect something that you've failed to hear.
An alternative is taking a break and returning after you're refreshed.
1. Don't just "learn" solos. Learn FROM them.Take "Stairway to Heaven," one of the most epic and well constructed solos from start to finish. If you dissect it, the idea is pretty simple. It begins with a connection of simple A minor pentatonic runs, followed by several more cool sounding licks to create one of the best written solo's to date.
For those of you who struggle with composing, think of licks as words and a solo as a sentence. Combine words to form a sentence.
You can easily get a lot of good solo ideas by listening carefully to other guitarists and incorporating some of it into your guitar playing and eventually create your own style.
2. Ditch the boring technique exercises.If you want to get better, don't waste precious time with generic technique exercises that you find all across the internet. These include legato, tremolo picking, string skipping, sweep picking, tapping etc. It's boring, tedious and is of little use if you don't know how to apply them to your guitar playing.
A smarter and more enjoyable idea is to pick any challenging solo (e.g. - Eruption) that incorporates elements of what you'd like to improve in your guitar playing (e.g. - legato/trem picking) and practice those sections (along with the entire solo).
You kill 4 birds with one stone!
1) You learn the solo (eventually).
2) You become a more skilled player in the process.
3) You stay motivated because you know you aren't merely practicing a mindless exercise that's going nowhere. You're practicing an integral part of a mindblowing solo.
4) You get a live demonstration on how to use a particular lick or phrase in a given situation.
That concludes my comprehensive lesson on transcribing and learning solos. I hope it's been helpful and will make you a better guitarist. Now get to it!