Lol I love this (off)topic as I just came home from my friends garage, doing a engine swap. Just lol.
Anyway, if you have done it a couple of times and you do research on the chassis you're working on, it shouldn't take more then 8 hours with the largers and dificult engines.
We are working on another MKII VW golf GTI to vr6/g60 swaps (this is the 4th already so it's become routine)
Yesterday afternoon we had a case of heineken and took out the engine in 2 hours (1 hour to drain everything included). It's a small engine and very easy to take out.
Then we made space and welded support for the larger vr6 and called it a day around 9:30 pm (about 5.5 hours for everything including keeping the meat on the grill under control and tend to the beer).
This morning I ran the wiring harness while he prepped everything (new tranny means new shift rods, bushings, dampers, etc. Popped in the new engine in about 30 mins and hooked everything up in another hour and some change.
Now what takes really long is getting everything finetuned to perfection and making sure everything is working fine and hooked up (fans, pumps, wiring, etc)
Tomorrow we have to brake it in a bit and change the suspension as the new larger vr6 is quite a bit heavier then the stock 1.8 four banger.
All in all it's 2 days for a full conversion with everything taken care of.
This is also a commercial job so we have to make sure everything works before we give it back to the customer. When we did our track car, you trow it in and fix things as you go. (although that was the first thing we ever did so we had no idea what needed to be done except from what we learned from the interweb

. And we did a lot more then just a vr6 swap)
So if it takes you 8 hours to open the hood and drain some fluid, you might want to look for another hobby as engine/chassis work doesn't seem your cup of tea.