Hi Ilovebettas... A picture would really help.
Most 29 gal. All glass kits come with an 'All Glass' or 'Perfecto' 2 piece hood. There is a black plastic base with a clear window in it, and the fluorescent fixture which sits on top of that. Sometimes if the plastic flange [lip] on the base that the fixture part sits over becomes warped due to heat, or there is a buildup of gunk [scientific term] at the edges, they can become stuck together. Carefully prying them apart with a butterknife might work.
Perhaps you have an 'Eclipse 3' hood? If that's the case, there should be a retaining screw in the centre of the clear bulb cover. After removing that, you have to squeeze the edges of the cover to free them from the retaining lip.
REMEMBER to unplug the hood first, and drying it and your hands couldn't hurt. Let the bulb cool down for 5 minutes. If you get the cover removed, then just gently grasp the lamp bulb and rotate it 90 degrees and gently pull it away from the hood fixture.
Hope this helps, but if not, try to determine the brand of light fixture you have and post it or a picture, and I'm sure someone will be able to help you.
