How to do the Duplicate Cheat on Resident Evil 5?

Ive got the ps3 version, And i pretty much get how to do the cheat. Where it losses me is the two lines in the beginning.

"Duplicate Items

Note: This trick requires two gamertags and two controllers. If you only have one gamertag, create a second temporary gamer profile to perform this glitch. First, sign in with both gamertags....

" I cant seem to find a way to create another profile... nor does any of my google searches. The Guide does not explain this way crucial step of the cheat....How to do the Duplicate Cheat on Resident Evil 5?
you need 2 ps3s for this.

I'll refer to your PS3 as PS3 A, and the other as PS3 B. (A is Chris, B is Sheva)

Start a game with PS3 A, and have B join it.

when you find an item (ammo, herbs, guns, etc, but NOT treasures) let PS3 B get it.

After they get it, then end co op play and kick them out, and when sheva is AI controlled again, then just ask her to give you stuff. this way, both players can get 1 gun, or both can get a bunch of magnum ammo.