There's some grey area when it comes to the necks of the ReBop. PJ is under the impression that all of then can have their rods pulled out through the truss channel. This was not the case with mine. The truss channel was a traditional channel that flares at the tips but is narrow in the middle. So, the first step is to see what situation you're in.
Take off your strings & string nut. To remove the string nut, put a piece of wood against the fingerboard side of the nut and tap it with a mallet or hammer. The glue should loosen & the nut will come off. Loosen your truss rod until all tension is off. Use a pair of vise grips & see if you can pull the truss rod out. If you can, you can just get a new dual action truss rod with 4mm hex key nut from AllParts.com. Be sure to measure the length of your truss rod & order the appropriate size replacement. You may need to wrap the truss rod in felt to make it fit snugly. You can get adhesive backed felt at most craft stores & it's pretty easy to do.
Here's a link to the truss rods available: http://www.allparts.com/truss-rods-and-nuts
If you can't get the truss rod out, you have 2 options.
Option 1: Order a new neck from Hanser (you have the option of Rosewood with pearloid inlays, or maple with black inlays). This neck will NOT match your body colour.
Option 2: Have a luthier lift the fingerboard & install a new AllParts dual action truss rod (the same one suggested above). Be sure to measure your old rod before ordering a new one. Should run you about $15 for the new rod from allparts.com. This is the route I went, as a close friend of mine is a luthier and I REALLY wanted to keep my neck matching the body. For me, this option was cheaper but it all comes down to what the Luthier is going to charge you. Get price quotes on the replacement neck from Hanser & compare what the Luthier estimates.
Hope this helps.