I should flush mine... I keep getting oil mixed in it =( poor head gasket needs to be replaced...

I flush by:
#1 empty radiator
#2 fill w/ water and let it run for a few mins
#3 drain water
#4 fill w/ 50-50 let it run for a few mins w/ cap off
#5 close cap, rinse off reservoir tank and fill that up w/ 50-50

i never messed around with the bleeder valve... i dont even know where that is