Attach the black lead first, followed by the red lead, and finish with the white lead.

Place the wire from the new battery onto the new solder bead.

Press the tip of the soldering iron onto the solder bead until it melts.

Slide the wire lead into the liquid solder until the wire goes through the center of the bead, then remove the soldering iron.

Continue with the other two connections the same way, taking special care not to solder two of the connectors together.