How difficult is it to replace wax ring on toilet?

It's a project but you can do this!

http://www.youtube.com/watch?v=ae0TzEAzDZw

it is not really hard to do, just make sure you buy the correct depth ring for the floor you are replacing the toilet on i.e. linolium, tile , hardwood. Ask at the store they will tell you.

I have had to replace my wax ring three times in the 40 yrs. I have lived in this house. Just recently, it broke and did more than $1,500 damage to my dining rm. which is underneath the upstairs bathroom. Ruined my DR table and chairs...what a mess since I was recovering from surgery at the time. Wanted to pack my bags and leave for the hinterlands. Call a plumber to make sure it's being done correctly and to save yourself grief.

Easy as long as you can lift the toilet!

It's not too hard to DIY. First turn your water off. Then flush to get rid of most of water out. Remove water still in toilet. Remove one end of water feed line. Take the nuts and washers off of the base. Lift toilet STRAIGHT UP. Clean old wax ring off of the bottom with a paint scraper (or something similar). Also clean old wax ring off of the floor. Insert new wax ring on the floor. Make sure your bolts are straight up (replace bolts if needed). This next part is where you could use an extra set of hands. Line up the bottom holes with the bolts and put toilet STRAIGHT DOWN. Replace washers and nuts. Very important to not over-tighten the nuts or you will crack the porcelain. Put the seat down and sit on the toilet to compress the new wax ring . At this point you may need to tighten the nuts a little more. Try to get them even on both sides. Replace water line. Use teflon tape on both ends. Turn your water back on and flush the toilet to ensure you have a tight seal.