with a little help (say 2 people working together) you can get the engine out in less than 90 minutes. It's almost freaky how fast it comes out.
The hitch is that, once the engine is out, you prolly wanna wash the engine bay down real well, do a new clutch, you have to service the radiator (re-fill, bleed it), etc etc.
anyway... I say 1 long day for a good swap....
It helps a lot if the shop has done one before. Make sure you take lots of hi-res, pictures of how everything is connected, both for the cooling, air/throttle, fuel, electrical, etc. to speed the process.