Place the desoldering wick on top of the existing solder ball.

Place the soldering iron on top of wick above the existing solder ball.

Hold the soldering iron in place until the solder melts into the wick.

Repeat the same procedure on the remaining two connectors.

Lift the old battery out of the iPhone. Be sure that all the solder has been removed before pulling the wires away from the board. The wires should come free with little to no resistance.