Bathroom Exhaust Fan & Medicine Cabinet Intsallation

Hi, I'm just moving in to a new apartment, and am looking to replace an exhaust fan and medicine cabinet in my bathroom. I have the replacements, and am pretty darn good with DIY, but I need some professional help on these two jobs. I've taken out most of the existing exhaust fan, but can't figure out how to remove the rest. The hole for the new medicine cabinet needs to be made about two inches longer, and I'm wary of doing the cutting myself.