Copy the data folder into your Dead Rising 2/ folder.

Make sure to make backups of all files altered:

data/datafile.big

data/frontend/startup.text (beginning intro screen) 

data/frontend/tut_saving.tex (tutorial screen)

data/frontend/str_en.bcs (added english text for tutorial screen)

data/frontend/fecmn.big (remove Zombrex and military HUD)

data/dynamicprops (folder for weapons)