Need help trying to play Metallica Song?

It is the second riff of Master of puppets, you know, the one that is really fast and it uses the first four frets and an open E string between notes (dont feel like tabing it). I dont know exactly were you place the power chords G5, sliding to F sharp 5, with the open E in between. I know you play the riff once, then you do it again, cutting it short and inserting theses chords, just dont know were, HELP!