I would suggest replacing it. How mechanically inclined would you say you are? On a scale of 1 - 10 , 10 being the most difficult. I would say this is about a 3. Just because getting to it is the most time consuming. One tool you will need is a 24mm socket with a breaker bar, or you could use a 24mm wrench. But I would recommend the socket. It is also a great DIY because you will learn a little bit more about your box.
Anyone else want to chime in on this one??
Let me know if I can help with anything else.
Mark