Whatever your opinion on Ice T's attempt to break world records with profanity on this song, it is still one of the best tunes for beginning to learn fast metal rhythm styles. The song is very simple in that it is almost entirely played on the Low E string. Even when chords appear, they are simple Powerchord stabs. The song is in Eb so you will need to tune all your strings down by a single note (use the ActionTab tuner!)
Although this song is fairly easy on your fretboard hand - you will need to work at control and technique with your picking hand. That's the key to getting this song right. It's all about getting the right rhythm - constant downstrokes and upstrokes, with notes dropped in at the right places on the 3rd and 5th frets.
To start with, just constantly pick the open Low E string whilst palm muting - use constant down / up strokes. Don't worry about putting in any notes yet with your fretboard hand - just concentrate on playing along with the ActionTab and getting the rhythm right with the open string. Train your picking hand to constantly palm mute with regular down / up strokes.
Once you can do that and play along with the first part of the song, start working on adding in the G and A notes (3rd and 5th frets). Keep practicing until you get unbroken flow in your play. It will probably take a while for you to adjust to co-ordinating both hands playing together now. Get the tune into your head, this will help you 'feel' for when you need to fret notes. Then work on adding speed once you've got the intro / main riff tight.
Songs like this will train your strumming hand to subconsciously pick at speed. After enough practice you won't have to think so much about your strumming hand and this leaves your mind more free to think about what notes to pick on the fretboard.
Follow the picking directions carefully for each song segment. Beware that different parts of the song have variations in rhythm - use your ear to guide you. However, once you can do the intro / main riff, the rest will be a lot easier to follow.
Once you can play regular and tight palm muted rhythms like this, you will be able to work on more complex metal rhythms and riffs, so keep at it!