Installing toilet total repair kit/ dual flush upgrade purchased in a big box home improvement store. Kit is supposed to be a no tool no tank removal. This doesn't apply our canister style Mansfield brand toilet.
Shut off water and flush water from toilet tank. Remove tank from bowl by remove all bolts holding toilet tank to the bowl.
Remove original valve from tank & all parts. To remove this style of overflow tube it worked better to insert pliers through the bottom of the overflow tube an hold the nut on the outside while turning the tube clockwise. When removing flush handle remember that flush handle nut is a reverse thread.