I've had better luck pulling both the motor and transmission out together than I have just taking the motor alone. It is a lot easier to take them as a unit out the hood than to try to pull them apart in the truck. It also makes putting the good motor and transmission back together easier if you have them out in the open. Just remember to pull the shifters and wiring from the trans before you let it all loose.
I've done a pull and install of motor and trans in an afternoon, but that was with three of us and a tractor with a front end boom instead of a cherry picker with a hand pump. The recipient truck also was already prepared to recieve the transplant.
I'd say it is possible to do the swap in 2 1/2 days if it goes well. With some practice and the right attitude you could probably get the whole thing done in a day. Do whatever prep work you can on the dead motor beforehand, it will pay off in time saved and in getting familiar with what needs to be done to get them both out when the time comes.