How does one get the switch to stay back in or get things inside the hilt after that?
Heat up the switch area of the hilt with a hair dryer or heat gun. (wear gloves, obviously) No more than 20 seconds at a time, as you only want to soften the glue, not melt it. Between heat applications, try pulling the switch out. Once it comes out, put the hilt down with the switch hole facing down to keep the glue in place. Do your electronics work. Then heat the glue up again to put the switch back in. Again, have it sit switch down until the glue cools and hardens.
Alternative: After you take the electronics out, heat up the glue until it runs out of the hilt. To put the switch back in, wrap electrical tape around the threads so that it becomes a press fit switch. I've read that it will hold up even in heavy dueling when you do this.