I did this before, except the other way around.. I helped my Dad put a V6 Runner engine into his V6 pickup, it pretty much dropped right in, although we had an auto engine going into a standard trans pickup, so we had to remove the flywheel and put a clutch on instead.
Make sure you take lots of pictures when removing all the various hoses on the left hand side, there's about 10 small tubes which can be very easily mixed up if not careful.
Edit:
We also had to remove the wiring harness off the blown engine, because the two were not the identical match, that was probably the most time consuming part.