Can anyone tell me if i have a chance of replacing some 4700 uF radial electrolytics with capacitors of the snap-in type? the snap-ins have thicker terminals and larger lead space, how could i possibly fit them on the pcb?
...which I would only consider if the pcb is single sided or double-sided with the tracks connected to the bottom (solder side) only. If the holes are metallized with tracks on both sides of the pcb connected to them, leave them as they are because if drilling destroys the plating on the walls of the hole you can't get solder to flow to the other side of the pcb (which you can't reach with the iron it because it's under the caps).
I work in industrial electronics where single sided PCBs are pretty rare, many are double-sided but most multilayer.
EDIT: " conformal coating" is the clear protective layer applied to fully assembled PCBs that need protecting against humidity/dust/chemicals.
I think you mean the "solder resist coating" that the pcb manufacturer applies to the parts that must not take solder.