To replace lamp globes, determine if it is screwed on or is fixed using screws. In case of the former, unscrew the old globe completely off the light fixture, and screw the replacement globe. In case of the latter, undo the screws that hold the globe in position, remove the old globe and replace with a new one. Tighten screws with hands.
Before attempting to replace a lamp globe, allow it cool. Wear a pair of thin rubber gloves to get a better grip over the glass.
In case of a screw-on type lamp globe, turn it counter-clockwise to unscrew it from the light fixture. Slide the replacement globe over the bulb, position it straight over the base of the fixture, and thread the globe in a clockwise direction. Thread carefully to avoid screwing in a twisted position.
In case of a lamp globe attached using screws, use a pair of needle nose pliers to loosen the screws. Support the globe with the hand when loosening the screws. Once the screws are loosened, gently tug the old globe away from the fixture. Then, slide the new globe over the bulb, and position it over the inner fixture base. Tighten the screws until the globe is fixed in position.
In both cases, avoid over-tightening when fixing the replacement globe as this can cause the glass to crack.