25 reps seems like a great rep range but its only great if your burning out on the 25th rep.The more muscle you have,the more fat your gonna burn.Your not gonna get very far doing 25 reps at 80% of your potential output.If you wanna get it done,you gotta go 100% intensity.Please be sure not to overtrain.5 sets of x amount of reps @100% is good,6 sets is plenty.
It seems cardio is going to have to be your new best friend for a while.I would'nt do any more than 4,45mins sessions per week to keep from losing muscle.
Make sure you maintain a quality diet.Dont take in anymore calories than you need but make sure you get all the vitamins and nutrients you need.
Also,make sure you train the rest of your body with equal intensity.You dont wanna end up lop-sided or unproportional,that will increase your risk of injury along with being anti-eye candy.
Good luck with it,and dont give up!