2008 BMW X3 differential leak

Hey guys and gals of /r/cars! I am looking at a 2008 X3 that I can buy for through an employee purchase program and get a really good deal on it. I spoke to our shop manager and he said the car is in great shape other than the rear differential having a slight leak. (http://ift.tt/2snBdZD) He said that I can buy the vehicle with the repairs he has already done to it as it is, or wait until he sends it to a BMW technician to get the differential fixed and charge me the cost when it's all said and done. I am not new to working on cars but I have never worked on a BMW before and have heard I would need some specialty tools if I wanted to take a crack at it myself so my question is, would it be worth having a tech look at it or is this something seal related that I can do in a matter of an hour or two and some googling? Thanks guys I appreciate the help! via /r/cars http://ift.tt/2tegrhW