Most chandeliers are fragile and contain crystal parts. You can just let the chandelier hang on the ceiling. If necessary, use a ladder to get to it. This way, no parts or crystals of the chandelier can be broken.
Make sure that the electricity is switched off, so that the lights are not on. Water and electricity do not mix well, this is very dangerous. Place a blanket under the chandelier so that crystals that may fall off do not break.
Use warm water with a small amount of dish soap without adding lemon. Lemon attacks the top layer of the crystal, causing it to lose its shine. Does the tap water in your area contain a lot of lime? Then take rainwater or distilled water for cleaning the chandelier. It is best to use a new microfiber cloth to clean the chandelier and crystals. Periodically dip the cloth in the warm water and wring it out thoroughly.
Clean the chandelier with the microfiber cloth by gently rubbing the crystal parts. You don't have to rub the moisture on the crystals dry after brushing. This evaporates by itself.
Make sure that the electrical parts of your crystal chandelier do not come into contact with water. To prevent the crystals from tarnishing, never place or blow out a lighted candle under the chandelier. And of course never gourmet etc. under a crystal chandelier.