Actually...
The stern light on both of my boats were the same kind (Perko?), and it was a royal pain in the neck to change the bulb- So much so that I replaced them with Aqua Signal Series 25 lights... I like the series 25 because it's got the same kind of bulb as the bow light (fewer types of spares to carry), and only requires that you take out 2 screws to change the bulb. Only drawback? More current draw (10w bulb instead of 5w bulb), but I think there's a 5w bulb available... The way the old light was set up, you need to remove the two screws and pry the whole fitting off the transom. On the back of the light fixture, you'll find 4 small screws (these may be under some sealant...)- These are what hold the whole thing together. You need to remove two of these (top or bottom, doesn't matter) and the whole thing will basically explode apart in your hand. Inside you'll find a half-sized 'festoon' type bulb. Change that, put the whole thing back together, and you're back in business. Don't forget to apply some new sealant when you put it back on the transom...--Jon BastienH23 '2 Sheets to the Wind' (Still for sale!)H25 'Adagio'