non turbo to turbo swap

I have a 1977 golf that is a non turbo/4spd and I would like to swap in a '90 1.6 TD/5 speed unit from a Golf. What would I need to make the swap and is a difficult "challenge"?
The "new" motor did not come with a down pipe so I will need to locate one of those also, any suggestions where to look?

Thanks!
Steve

hi mate your probally have to make a downpipe which isnt to bad if you have a mig welder