basically flip all of your fans to exhaust out the front
hot air travels up and not sideways or downwards unless you have a 3000rpm fan blower moving that hot air to the front/bottom of the case.
the issue with the H70 and all closed loop coolers is that they need fresh, cooler air which means having to run them as intake and if you want them externally mounted, you'd either need to cut up the case or mod the H70 which won't bode well for warranty's sake.
have the rear as intake and have the top case fan as exhaust to vent the hot air out - as lowjack mentioned, but don't reverse the fans in the front.
given due time, you'll outgrow your cooler to loath it