My worst electronic nightmare has come true. Want to learn how to unsolder & replace a BGA ICs.

Unsoldering is going to be easy, right? - just use a SMD hot air station to blast the IC and remove with tweezers? What is the success rate of removing a good BGA device unharmed from a PCB?
Probably should use some reflective foil tape placed strategically around the BGA device to prevent too much heat going into surrounding components, too?

And what about replacing with a new BGA device... what's the technique used to resolder them to the PCB? Will surface tension of molten solder help 'pull' the BGA device into perfect alignment, or....?

I'm fairly experienced at SMD soldering of regular components eg: SOIC etc.