You are asking us because you just want us to remove the two pstones just for you? What about everyone else? What if he comes back on and finds that his place is griefed and his pstones gone?
We can't do things just because you want it done. If something needs to be done, there needs to be more than one person inquiring about the same thing. I would agree that a one month desertion or over is a pain, but you can't assume that they're NOT gonna come back on again.
Oh, and one other thing...
USE NETHER PORTALS AT YOUR OWN RISK