Why go through all the extra steps (and potential for problems) by desoldering the entire defective switch and replacing it with the new one? Simply open the defective switch and the new switch and take out the defective copper spring and replace it with the good copper spring from the new switch. If a piece goes flying (the white button or the spring), use the new one as a backup. Going through all this extra hassle is begging for problems. Also, don't bother trying to repair the curve on the defective spring. You'll never get it 100% perfect as new. It WILL fail again eventually. So just swap out the springs and move on with life. If you screw up the switch covers, you can use black electrical tape to seal the edges. Don't use glue.