[header] How to install a toilet handle [title] Lift the lid off of the toilet tank and make sure the tank is empty. [substeps] If the toilet has been in use previously, shut off the water supply to the toilet, then flush it to empty the tank. If this is a new toilet, do not turn on the water supply until after the handle is installed. 
[title] Hold the handle in your non-dominant hand and remove the gasket and shank nut from the back of the handle. [substeps] The gasket is a rubber ring that sits behind the nut and helps to seal the handle from leaks.