does not matter that much but

turn off boiler and pump.
if 2 floors do ground floor first.
Leave heating on at max on boiler for about 2 hours ( you do this because when the water temp in the rads get to 65 the air in the water will seperate and gather in the top of your rads again )and then switch off including pump and go round and re bleed rads.
then switch back on and set boiler and programmer back to your normall settings
If you follow that you should be ok