why dont u try flirting with 1 of the boys in halfords and get them to do it quickly.

it should only be a 5 minute job tbh.

what car is it going in?

it should be a case of taking the old one out, and plugging the new 1 in, either directly or through an adaptor lead.
if u go into halfords and tell them what the car is and what stereo u want they will tell u if its a direct replacement of i u need an adaptor lead