Halogen bulbs with two pins, often called bi-pin, are typically used in under-cabinet lighting, spotlighting, and ambient lighting. These bulbs come with the base designations of G and GU. The low voltage 2-pin lamps can be distinguished from their 120-volt, 2-pin cousins by the shape of the pins. Low voltage lamps have straight pins, while 120-volt lamps have pins with a cap near their tips. Low voltage, 2-pin halogen bulbs may come in the shape of a capsule like the G4 JC12, or can be round, and up to 5 cm (2 inches) in diameter, like the very common GU5.3 MR16. A very common 2-pin halogen bulb that operates on 120-volts is the GU10 MR16.
Turn off the power to the light fixture.
Wait until the bulb to be removed has cooled.
Push in and turn the bulb counterclockwise using your gloved hand until it stops, and then pull outward from the fixture when removing a 120-volt, 2-pin halogen bulb. Some of these fixtures, especially overhead track lighting, may not allow enough room to get your fingers around the bulb. Use the suction cup on the face of the bulb to get a grip on it.
Grasp the 2-pin, low voltage bulb with your gloved hand and pull it straight out from the fixture.
Grasp the replacement bulb by its edges using your gloved hand, insert the pins into the holes in the socket and twist clockwise to install a 120-volt, 2-pin halogen bulb. Use the suction cup in those situations where the light fixture shade interferes with installation.
Grasp the bulb by its sides using your gloved hand, line up the pins with the holes in the fixture, and then push the pins into the holes until the bulb locks in place, when installing a low-voltage halogen bulb.
Turn on the power to the light fixture.
Wear safety glasses. Don't touch hot halogen bulbs. Only use replacement bulbs that match the wattage and design of the fixture.