It's fairly straight forward, especially if you put engine with gearbox. It took me one day to take it off and drop other in and then another day combined to connect everything as it should be (except wiring). I do have paperwork prepared already for wiring, just need to find a day to connect all together.
Altough I need to warn you, that it would take a bit longer and more fiddly if you do it on a driveway. I'm fortunate enough to have my own workshop with lift and tools. Only parts you will need to exchange are: fuel pressure regulator bracket, power steering top container, 2 pipes from heater matrix to engine, engine mounts from 2JZ, accelerator line and in my case I had to replace gearbox linkage with 2JZ one (I was using original 1JZ auto box).
If you are fairly mechanically minded person, you should handle it no problem.
Fuel pump change is even simpler and you can do it seperate, so it will not distract you during engine swap.
http://www.mkivsupra.net/vbb/showthread.php?45647-How-to-change-a-Supra-fuel-pump.&p=2002718&viewfull=1#post2002718