On the t-case end or the diff end? On the T-case end you need to pull the flange to replace the bolt as there is a big C-clip behind the bolts. On the diff end, just take the bolt out and replace it as it is not threaded into the flange or anything like that.
If you are talking about the one in the hub, then good luck getting it out. I ended up just buying a new hub as they are hardened steel and very tough to drill out.
*not legal advice*