What should I expect for the MEPS physical I have on Friday? Any pointers to pass?

Don't do drugs and don't drink the night before. That's basically all you got to do to pass

Looking at your comments you will be fine -
Funny story about my MEPS experience -
The wise guy that was first for the old a-hole check messed with us pretty good. When he walked out he was walking funny and holding his ass. He was shaking his head and said something like - "felt like his whole fist was in there." Caused everyone to pause for a couple of seconds.

There are no tricks, no cheats. There is nothing you can do to pass. You are either physically fit to server or you are not. If you have done drugs, ie the illegal kind, best to not go and get clean then try again. You will be tested and it will show up. You will undergo a full physical, they will draw blood to test for a variety of things. You will be tested for Asthma, they will take xrays of your mouth of your chest and abdomen. You will strip down to your skivvies and walk around, bend down, stand up, lean over, lift and do range of motion. Prepare to drop your clothes and be told to turn and cough while you are probed.

General pointers though? Don't take the normal crap with you. No lighters, cigarettes, guns, knives, walkmans, Ipads, Ipods, Cellphones... none of that. Leave it at home. Take a book. Be prepared to be bored. Sit around and wait is common. When your name is called be prompt in responding and doing and do not be a smart ass to the staff. Good way to get your butt sitting in a seat while your recruiter comes and collects you.