Ben there, done that, Used to use a shop light that clamps onto the side of aquarium during maint. This worked well so long as filter was off. However one particular day ,i was simply going to change water, Removed the glass tops on one side and neglected to turn the filter off. Splash from water entering the tank from filter ,splashed up and hit the hot bulb and shattered it. All pieces fell into the tank. Had to remove the fish and try and net,or pick out all the pieces. I then used gravel vac to try and get the tiniest pieces.
I would try and do something similar if it were me. With one fish, you could leave the fish in the tank. I however had numerous large fish that were swimming about and causing the pieces of glass to become scattered. Is only reason I removed them.
Chin up,, Many things are difficult before they become easy.