Main riff:

e|------9------8-------6-------8---------------------------------|
B|---------------------------------------------------------------|
G|---------------------------------------------------------------|
D|---------------------------------------------------------------|
A|--8------8-------8-------8----------8--6--4--------------------|
E|---------------------------------------------8-----------------|

Alternate riff:

e|------9------8-------6-------8---------------------------------|
B|---------------------------------------------------------------|
G|---------------------------------------------------------------|
D|---------------------------------------------------------------|
A|--8------8-------8-------8----------8--6--4--------------------|
E|---------------------------------------------8---6-------------|

This is the short lick right before eminem comes(1:34)

e|----------------------------------------------|
B|---------------------9------------------------|
G|------------8-10-11---------------------------|
D|----8-10h11-----------------------------------|
A|--8-------------------------------------------|
E|----------------------------------------------|

Eminem's beat does this at first:

e|------9-9-9----------8-8-8---------6-6-6----------8-8-8----------------|
B|-----------------------------------------------------------------------|
G|-----------------------------------------------------------------------|
D|-----------------------------------------------------------------------|
A|--8-------------8--------------8------------8----------------8-6-4-----|
E|-------------------------------------------------------------------8---|