If you take the 510 threaded bottom cap off (using the stand/tool), you can break the Rose down even further. Just be careful, it can be difficult to reassemble.
One the bottom cap and grub screws are removed, remove the screw from the white delrin section. Once removed, the whole positive post/section will slide out. This should solve your problem.
To put everything back together, I find easiest doing this. Insert the positive post, then slide the delrin piece into place. Next, fit the grub screw into the positive section and leave the allen key in the screw. This will keep the positive post from rotating as you tighten the screw back into the delrin piece.
Best of luck!
PS. Still waiting for my replacement parts from Eden Mods. They supposedly sent them out.. oh.. about a month ago now. They said that "sometimes things get lost in the mail." Of course, there was never a tracking number. On friday, they told me they would send out a new replacement part with tracking this time. Yeppp, no response. Bought myself a clone today. It's a shame this British company doesn't live up to the lofty standards their fellow Brits place so highly on them.

Darn fine atty, though.