If it's mounted on a printed circuit board then I'd recommend (insist is closer) a temperature controlled iron and some desolder braid. I've used desoldering pumps on PCBs before, but what you want to do here is avoid melting the copper tracks on the board. The trick is to get the iron hot enough to melt the solder, but cool enough to leave the PCB undamaged. I've found braid more successful for this.
Top tip No1 though is that when you're removing solder from a board apply a little bit more solder to the joint as this helps the other stuff melt easier, and you're less likely to damage the board.