I made the hole big enough for the sidelight bulb to push in (with a bit of force) but small enough for it not to fall out, and once it was pushed into the hole, that's where it stayed. Only problem I ever had was cheap connectors that kept wanting to fall off the end of the wires no matter how many times I 'crimped' them. Gave up in the end and used tape

Also, I forgot you're running standard clear indicators. I believe they do have an orange filter inside them so you'd be fine with just clear bulbs. My car had smoked indicators with no orange filter hence why I had to use orange bulbs.