There are two techniques to unsolder the three prongs.
One is to use solder wick or a desoldering tool to remove the solder from the pcb and the pins
The other is to add more solder to all three pins keeping them all in a liquid state until the pcb can be lifter off.
I use a Masonite block that is cut to fit into the bottom to apply pressure on the wheel components when re soldering everything back together. This keeps everything tight in case the little lock tab has been bent back too far and no longer holds the pcb.