(T) Fitting elec windows/central lck

Right done a search but nothing ive seen helps me so hopefully someone can shed some light on my problem,gettin all the parts needed for conversion but i dont have the connections under each side of the dash!!!

Got all the bits from inside the doors including looms but where do i wire up2?? do i need another relay for elec windows and the central lockin as the car ive got the bits from i can get wiring from behind the dash when its removed.

Is this an easy job to re use existing wiring from donor car or is there an easer way where i can hook it up2.

gaz

Anyone???????????