Ok man I got you, first I warmed up and I did some galloping because my picking arm was able to alternative picking as fast so I just played over some songs I learned and I listened to before. If you listen to Metal some examples would be almost any Iron maiden song, if you listen to Metallica it would be Battery, Slayer I guess Raining blood, but for me and I highly recommend you the first half of Megadeth's Devil Island. You can easily slow it down if you can't pick that fast because the riff is so simple. After my warm up for the right hand I started working on my left hand. So what I did is I started on A (5th frett of the e string) note on E(6) string and I did this (I will try to tab this) :5-7-6-8. Play it like : 5 index finger 7 ring finger 6 middle finger and 8 with pinky . Then I moved it on A(5) string 5-7-6-8 and I did the same thing, then D(4), G(3), B(2), and E(1). Then for coming back up on the fretboard I did 8-6-7-5 with same fingers on the same fret as before. Then I moved it from 5(A) to 6 fret and repeated the exercise but now I would play 6-8-7-9 and 9-7-8-6 on the way back and again movie it to 7th fret and did the same and so on till the 12th fret. Its important to play this in tempo and to play all the notes. Don't rush it. And then I had a pause. When I mastered this exercise I simply speeded it up. But I always played it in tempo. When I could play this subconsciously I started to watch films while doing the exercise so I wouldn't get bored. Someone said that you will be able to play really fast after doing this exercise for 15 min a day 2 weeks. I did it 2-3 hours a day and 1,5 month. It literally made me go from rhythm guitar to lead. Hope this helps! If you don't have enough time to do it as long I did do it at least 15 min a day and you should improve. But do play in tempo and and do work on your right arm as well.