Is a flapper easy to install or should a plumber do this procedure?

Hey Tony, Good morning. A flapper replacement is one the easiest repair jobs going. Let me show you how. Shut the water off at the angle stop located under the tank and flush the water out. If you have a newer toilet you will see where the old flapper hooks onto the base of the white overflow tube. On a older type with no hooks the flapper has a ring that slips down over the overflow tube to the seat. If your tank has hooks, take a sharp knife and cut the neoprene ring off on the marks provided and hook the flapper on the hooks. Now attach the linkage,(chain) to the flush lever. The chain should have 1/4" of play when the flapper's seated. Now turn on the water and give it a flush. And that's how to change out a flapper. Good luck and thank you for rating my reply. Tom