Bathroom shower hot/cold reversed?

So I have a shower in my house that when built a long time ago, the hot and cold were switched. The shower has a single handle for the water. Normally, the handle all the way up would be hot and the spot closest to the 'not off' position would be cold, however, mine is opposite. The shower is obviously finished off and its a guest shower so no one really cares, but is there an 'easy' way to switch them to how they need to be or does that require tearing out the wall? I have no idea how they are connected inside. I didnt build the house, we just moved into it. It was caught in the inspection, but we were informed that the fix would be to tear out the wall....i dont know. The solution for it at the time was to put H and C stickers in the proper locations. I just was wondering if I could fix it properly.

There really isn't an easy way. If there is a closet wall on the other side of the shower then open the wall and see how the water is plumbed. That would be the place to fix the problem

Depending on the manufacturer it may be as simple as turning the handle 180 degrees.

Who makes your valve and if unknown can you post a picture?

After looking through the Kohler website, im nearly 100% sure its a Kohler Kelston.

It is possible that the stem may be 180 out.
I'm not playing on their website to see for sure...
I'd rather have root canal sans novacaine then navigate their site.

With the Trim removed turn the valve to hot and see if the hot feed is on the left side entering the valve.

If it is rotate the stem 180 degrees and reassemble.

Typically the transition from cold to hot is abrupt when this is reversed.

valve

Many valves are symetrical so you can remove the operating mechanism, rotate it 180 degrees, and reinstall it to reverse the hot/cold orientation.