The head can get pitted too from the old coolant.
I use a wet vac to change coolant, works great and leaves the vac nice and clean. I just pull a radiator hose and slorch it out.
After refilling, it's easy to bleed the system by applying pressure to the coolant tank. You can use a cooling system pressure tester, or what I do is:
Pull the vacuum line to the heater valve or leave the key on and heater set to full hot / defrost (engine off)
Clean the end of the overflow hose
Leave the filler cap off
Right hand over the filler neck to seal it, left hand on a wrench on the bleeder screw, coolant overflow hose in your mouth.
Blow - open bleeder - close bleeder - inhale
Repeat, make sure to top off the coolant as needed. Air and then coolant will eventually come out the bleeder.
Rinse out your mouth, and do not swallow any drops of coolant that somehow might have gotten in your mouth. I swish the end of the overflow hose around in some water and wipe off the dirt on the outside. Never had a problem.
After that I run the car up to temp and burp it once more when fully hot. Easy!
-Joel.