i get it now
[as usual, always make backups *cough* graveyard *cough*
1) copy the dummy save from PS3 to a usb
2) open up the save folder and look at the .sav file
it should say save000X.sav
3) copy your gaige's .sav over the dummy .sav
4) decrypt pfd
5) open gibbed and change the save slot to the number from the .sav
6) change character, mod guns, etc
7) update and encrypt pfd

bring the usb back to your PS3
9) pray the save doesnt show up as corrupted
10) copy the save over
11) Profit
Edit: this is how i did it