Play -9-10-11-12- repeatedly on the 6th string..1 finger entitled to 1 note..
Play as slow as ONE second PER note..make sure ur fingers are very near to the fingerboard and ur first finger is always pressing down the 9th fret (not jumping up and down)
Lastly, u hav to hear the sound dat is coming out of ur amp are of 4 notes..not some unclear tabs like deng-deeng-bum-deeeeng-..this may happen because u are trying to adapt ur fingers to stay near the fingerboard..u hav to avoid the 'bum' or watever shit sound..
This technique of nearing ur fingers to ur fingerboard is for the sake dat u could shred perfectly..FAST yet CLEAR NOTES..if u juz shred but sound shit,why not u juz do some pickslide? aha..
So yea..i learned dat from a fren of mine who could play speed kills by michael angelo..i didnt follow wat he said at first,coz yea,like me now,i sound dumb by teaching u this..but hell,if u wanna be a pro,u hav to start from scratch..Every new thing u learn,how fast the shredding is or how slow,u hav to adapt ur fingers for as slow as u can..and i mean really slow..like the practice written above..even sweeping,do it damn damn slow,and i'll tell u,in a week,u can sweep like Malmsteen..forget about canon rock..it tempts u to learn quick..
Patience is wat u need..
Hope u heed my advice..and those who believe this practice always work,please give some kudos so this bro would actually think about it..