You will need:
Various assorted screwdrivers
Drill and bits
Sandpaper or sanding block
A gumball machine on a stand. Do not try this with square gumball machines. They must be round, preferably glass.
Glass and glass cutters (or the phone number of a glass shop)
Silicone aquarium sealant (must be aquarium sealant, as bath sealant is not as strong and may contain chemicals that will harm your fish)
Rust-proofing spray paint
Push-in rubber grommets
Nuts and bolts and washers as needed
Some scrap aluminum
LED Betta light
Small aquarium filter (I used a Penn Plax Smallworld Filter)
3-plug extension cord with grounded prong
Step 1: Disassemble and clean
Take the whole thing apart carefully, and clean everything really well. If paint is cracked or chipped, don't be afraid to sand it off and repaint it. I didn't need to. I did remove the crumbling 10c sticker, even though it would have looked nice. There was a cork ring between the steel on the top of the globe which was stuck to the glass. I scraped it off and sanded the edges of the glass down. If the steel parts on the bottom of the machine are stuck on, try to get them off. They've likely just stuck from age and pressure, and aren't secured.
Clean the entire inside of the globe with rubbing alcohol and let it dry out.
At this point I also took the stand outside to sand and paint the bottoms of the legs, which were in bad shape.