Should be a piece of cake. Springs and switches easy to find. LEDs are no problem as long as the pcb you go with has a place to source power from. If you don't want to mess with the PCB at all, just solder the LEDs to a battery box and hook the battery box up to a switch. Then you can keep the lights and the electronics separate from each other and have the added bonus of being able to turn on/off the lights separately!