Here's a,summary of desoldering techniques.
https://m.youtube.com/watch?v=77JgIqraX_I
I've got a soldering pump but for years I used th flux and desolder braid technique. I desoldered 40 pin chips this way with no problems, as long as you do diagonally opposite pins to stop overheating the board. Once the solder has been sucked out wiggle each pin to break any adhesion - if it doesn't free up use more flux, more heat & braid. Practicing on an old board that doesn't matter is an excellent idea.