Instructables

Mod a Ricochet radio modem to take an external antenna

Step 5: Prep the board for the new jack.

Clean up all that nasty solder residue by "mopping" the area with some absorbent braid. It works just like a towel, but for molten metal. Isn't that a fun concept to contemplate?

Use flux, and hold the braid far enough back that you don't burn your fingers. Copper is a very good heat conductor!