To replace a shower in an RV, first turn off the water supply to the vehicle by removing the city water hose and disconnecting the water pump. Remove the shower access panel and the hot and cold feeds, and disconnect the vacuum breaker and the faucet and shower head pipes.
Clear the shower stall of all accessories before removing the original shower walls. For sectional showers, remove the top piece and then remove the remaining sections from the top down. Look out for decorative trim or fasteners hidden behind shelf supports or mirrors. Remove the original shower pan and any adhesive pads below it and avoid damaging the plumbing fixtures that move gray water.
Measure and write down the dimensions of the shower by height, width and depth to find a new installation that fits properly. Also consider the weight that new materials might add to the RV's carriage. Many new shower installations come with instructions that need to be followed precisely to ensure the plumbing and fastening is correct. Once installed and if needed, caulk the shower panel edges and the shower pan and allow it to dry and cure before use. The installation instructions indicate the type of curtain rod or door to purchase that fits correctly and is easy to store when the vehicle is in motion.