advice much needed

i'v come to the conclusion that i have to rewire my entire car. at the moment it has the bullet point fuse board. the car was originally 1.3 but i'm putting a 1.6gti engine into it. the gti loom that i have is from a fuse board with the more modern fuses.
has anyone ever rewired the entire car before??
how hard is it??
and is there anything that i can do to make the change over easier??

as we have stripped many golfs the wiring loom is easy . it is best to buy a donar car  . we can do a loom change in 3 hours

if you have the later loom with the blade fuses that loom is for the 1.8gti all 1.6 gti's had the bullet fuses, if your fitting a 1.6 you will only need the engine bay injection loom and the rear loom, you can fit the 1.8 gti loom, but then u need to change it all.