Your best bet for getting Windows Home Server 2011 installed is to locate an adapter cable for the I/O header on the motherboard (I think the x310 has one, like the MediaSmart Servers do). Using it will require mostly disassembling your server, however.
Once you've done that, you'll be able to see what you're doing, and will have an easier time of it.
I'll warn you that any custom hardware (drive lights, for instance) will not have drivers for the new OS, and so won't work, and it's unlikely that HP will release drivers for Windows Home Server 2011 for the x310, I'm afraid.
I'm not on the WHS team, I just post a lot. :)