I’m not sure if you’ve tried this or not, but I figured I’d mention it anyway. Try adding some new solder to the old solder to get it to melt, then extract the component leads and use your desoldering methods to clean up the pads.
To do this, I keep my soldering iron tip against the old solder and press some new solder against the tip. The molten new solder with its flux always seems to get the old stuff flowing again. Best of luck, Royce
