I got a great gameplan for you and some nice tips for you, and I love helping people out.
He definitely seems to be a physical guy, he loves the clinch, and he likes to use his strength to muscle people around. He loves to grab onto the fence and keep you there and deliver some knees as well. So watch out for that. His cardio doesn't seem too great, and his striking is probably no where near yours.
So here is what you should do:
Work on your cardio and make sure you're in tip-top shape for this fight. Work on your wrestling for sure. I would try to mix it up and keep him guessing, and keep him off balance. Unbalancing an opponent is the best way to defeat them. Work on your wrestling and mix in takedowns, and pick him apart on the feet. Use body kicks, leg kicks, knees, and whatever you possibly can. A fight you should study is the second Frankie Edgar-BJ Penn fight. Frankie kept BJ guessing and off balance and won.
Have an answer for anything and everything he gives you. For his clinch, there are a variety of things you can do.
-Work on your clinch defense, and try to reverse the position if he gets it on you.
-Again, work on your wrestling and you can attempt a takedown.
-Knees and uppercuts!
-Pulling guard.
*Only pull guard if you feel comfortable off your back and make sure you stay active! Many MMA fighters have very dull guards, so make sure you stay active and STILL keep him off-balance. Threaten him with submissions, and stay active off your back delivering elbows.
Make him fight your fight, and when he tries to make you fight his, beat him at it! Have an answer for everything he can possibly give you. Keep him off-balance and keep him guessing and the fight should be yours.
Good luck!