Yours is like mine. I have not had to replace the bulb, but I did pull it partially off to reseal it. My wires are to short as well to pull it off far enough to access the bottom and replace the bulb. Luckily I don't have to yet
But what I would do is see if you can access the wires from underneath. If so, see if there is extra to pull on and get the light off farther. If not, you will have to cut them and rewire longer wires. If you have a cabin, rewiring it would probably be easier because you would have to tear away material to access them from inside. I can feel my wires from inside the cabin, but I don't want to tear the cloth out. I would give a little tug on the light. If the wires won't pull out, cut them. Adding a couple of small extension wires is simple. I wouldn't yank the light out though, cause you could damage the leads on the light. Make sure you cut them. And don't let the wires fall inside the boat after you cut them
Good luck
If that don't work, grab a case of beer, take Hammer's idea and cut it out