if you have access to an engine crane you should be able to do it within a day

it took me 2 days to fit a TDI into my mk4 but loads of things had to be fabricated and i wasnt really rushing with it

if you can get hold of an early engine it wont have a PATS coded pump and all you will have to do it get a ignition live to the fuel shut off solinoid

if you get a later engine you have 2 options,
1. make sure you get the key , PATS unit and any relevant loom from the doner car and fit into yours , or
2. take off the fuel pump and cut away the shroud at the back that covers the fuel valve then snip the wires and re-wire onto a ignition live

i chose the latter with mine as the belts were being replaced anyway so its not much more of a job to take the pump off