My Xbox 360 is overheating?

My Xbox 360 quit working a few days ago. It gives me two red lights on the left hand side. I've also acquired the error code 0013. Both of these are indicators of overheating. I never move my xbox, nor have I ever dropped or banged it etc.. I keep it on a clean, hard, flat open surface and dust the area and the xbox itself regularly. As you can tell, I've actually taken every step possible to prevent this from happening! I've given the console over 48 hours to cool with no result. I also tried hoovering the ventilation holes to suck out any dust (although there shouldn't be any there as previously stated). My guess is that a fan inside has stopped working. The warranty was up 7 months ago and microsoft wants $99.00 to fix it. RIP OFF! I was wondering if any tech experts out there have any suggestions on how to fix this problem without sending it in and getting robbed of a hundred bucks. I'm not a huge tech guy and I don't want to mess it up further by trying anything too complicated but I'm definitely up for suggestions.