2007 Honda Rincon 680 Slipping

Hi guys i have a 07 rincon and seems its slipping under loads. Like i road it yesterday and it did alright till i went in some mud them it would rev up but not turn the wheels! i just as i get the BRGR on it to make it have more power for the mud and now the dam transmission is slipping. Its wired though cause some times it will go and ride and other times it will hardly want to move. This morning i use it to move my trailer around the yard and it didnt want to pull it so i gunned it and got it to move but make a smell like a the clutch was getting hot then i let it set a bit and tried again and moved it with no problem. I had read something about oil pressure and o rings where would i find a shade tree guide on how to do the o rings ! i find it easier to watch a video or use a guide from a another rincon riders point of view rather then using the honda Manuel which is like talking in doctor to me. I have changed oil on it so i know thats not the issue its been doing this since i got it and seems to gotten worse over the years.