once again, hard to say without seeing it. def need some kind of intake as well as output if the temps are that high. best I can say without seein is to cut the intake low and the output high (as we all know, heat rises). you could try duct booster fans. 6 or 8 in should do it, unless you want to go all out and buy a vortex fan.
once you set up somethin you can play with it and adjust the results your getting within a few degrees. but if you run an outtake you should def see those temps drop. You'll be good if you can get it down to like 82-84
if you need to look at what you need to do ahead of time just google theres tons of pics of that stuff right here on riu