Prime the desoldering pump by depressing the plunger.

Heat the solder joint until the solder is liquified. To help with heat transfer, add some solder onto the soldering iron's tip.

Position the pump's nozzle as close to the molten solder as possible.

Press the side button to activate the pump.

Repeat the process until the joint is clean. You can also use solder wick to help soak up any remnant solder.