It was a non-event for me. Here is the process I use:
Try to catch the coolant that you spill so you have some idea of how much to put back in. After loosening the housing bolts, I slowly pulled the housing away and caught most of it in a shallow container.
After the install, jack up the passenger side of the car so the bottle is higher than the engine. Add new coolant to the bottle, approximating the amount you lost. If you aren't sure, just make sure it is well above the full level.
Start the car with the bottle open and let it warm up until the thermostat opens. You can tell when the hose get hot and and gauge is nearing the normal level.
Rev the engine to around 2500 rpm for several seconds, then back to idle. Repeat the rev/idle process 3 times.
Shut off the engine and let it cool. It should have sucked the new coolant into the engine replacing the air. Check the level and add if necessary to just above the full line. Check for leaks and keep an eye on the level for a day or so.
This process worked fine for me. Others may have other suggestions.