The problem with heating the leads from the rear while pulling the capacitor out the other side is that if the solder cools while you are yanking (or something is stuck to the leads that is bigger then the hole) you have a good chance of pulling out the metal layer in the circuit board itself. Boards can be multi layer with circuit connections in multiple layers while the hole is plated at the factory. If you damage that connection there is no real way to fix it.