#2
to learn the 16ths what u do turn ur metronome to click each 16th note, then match ur alternate picking to it (strumming just the open E)

once the speed is then match proceed string by string, getting comfortable hitting the notes cleanly and clearly before progressing on to the next string and therefore combining multiple string pattens

hope that helps for a little bit of extra help
#3
slow down the beats per minute as far as you need to get all of the notes in the riff PERFECTLY precise, and slowly work your way up untill you get to the speed you want to. It sucks and can be tedious, but sometime you have to start slow, or painfully slow..lol. It will be worth it in the end.

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#5
to learn the 16ths what u do turn ur metronome to click each 16th note, then match ur alternate picking to it (strumming just the open E)

Alternatively, fit four notes into one click. I prefer to do it this way, because then you would find it easier moving to weirder groupings (threes, fives, elevens if you're Paul Gilbert..)
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