Remove the connections from the speakers.

Replace the old speakers by soldering the four wires onto each connector of the new speakers.

Check out IFixit's official soldering guide for help with these special projects.

Soldering iron will be very hot.

If you disassembled the Flip 2 to replace the speakers, you'll need to find suitable replacements. The Dayton Audio CE40P-8 is a 1.5" diameter, 1" deep, 8 ohm speaker that works well, as explained in this video.