Welcome to the AF!
Check out the '99 Factory Service Manual linked in the sticky post at the top of this forum. It is directly applicable to your engine and will tell you everything you need to know about the procedure.
http://oregonstate.edu/~tongt/camry/99/index.html
It is not too difficult, but it will take a while if it is your first time.
Replace any leaking shaft seals, replace your water pump (as you said). Test the other components as outlined in the manual.