That can be a challenge ....
Some Wal Marts will do it.
If they hesitate I've heard of guys telling them it is for a specialty trailer and to mount the tire like it is on the left side.
Some shops that deal with nice rims will do it.
I'm fortunate, in that I have a local tire place that will do mine for $15.00. I carry the rim and tire in already off the bike.
Once you get it done the first time, it can be a little easier, because the rim already has a CT on it.