To replace a toilet cistern, start by turning off the water supply and draining the cistern. Disconnect the water inlet and overflow pipes, then remove the old cistern by unscrewing it from the wall and the toilet bowl. Position the new cistern, connect the water inlet and overflow pipes, and secure it to the wall and toilet bowl. Turn the water supply back on and check for leaks. For... https://tapron.co.uk/blogs/news/how-to-replace-toilet-cistern