how come some people can easily copy a song especially, a song which include fast solos ? is that just a matter of talent ? or there is a methode to do it ?
You have to learn it slowly, to a metronome and gradually increase the speed. Start it at say 100bpm get confortable there, raise it by 8 bpm then get comfortable there until you reach the desired speed.

The answer to this question is always use a metronome...been playing 8 years and I still need one
so it`s just like doing improvisation with metronome in order to improve and used to fast melodic isn`t it ?
Kinda, the first step is to memorize it all. Then you need to patience to play it real slow and take the metronome up 4 bpm every time but don't speed it up until you can play it 100% at your current speed.