Here is what I do:
1) Remove the crossover tube cap.
2) Start the car and let it run for like 15 minutes or until it comes up in temp to open the t-stat. (usually around 15-20 minutes)
3) Wait for the coolant to go down, and then replenish the coolant thru the crossover cap opening. (you may hafta do this several times, as the rad cools down the temp the t-stat will close, once it opens again the level MAY go down again).
4) Repeat 3 as necessary to fill the system up.
5) Fill the reservior up to the hot level.
6) Turn off car.
7) Put crossover cap back on.
Hope that helps.