hi guy here my guide and i want break in 3 parts so im very sorry but this the only way i can do.
Firstly when your done downloading it paste z_spetz1.iwd and z_spetz2.iwd to call of duty 6 path called /Main/ folder
when your done on the first step come to this last step paste mp_crash.ff to /Zone/English/ at your call of duty 6 mw2 folder when your done start the game enjoy. hope i helped you