its relatively easy if you have a later spec golf. that way the wiring is all the same, bar two or three wires. what u need to get the best fit and make life easier is:
The whole dash,
the metal support which runs from one side of the car to the other,
the center consol,
fibreglass,
longer heater cables,
clocks,
steering wheel support from a mk3.(bolts onto metal frame.)
and lots of patience.
You have to cut a lot of plastic away from the rear of the dash, and a bit from either side, also you will have to figure out a way to make the instrument panel fit around the existing steering column, unless you do the cross frame as mentioned above, cut the cross frame down and weld it in and youll find it really easy.
If you do decide to go with it, (and it is worth it) then i'll source out the wiring diagrams for you, if youve got a pre 90 spec then i can definatly help u with that but the post 90 spec is easy.
One point to note is that the heater controls will work backwards.
