As Hakzaw mentioned, it could be very difficult especially if the components are glued with the same type of glue that their Ti-B's are assembled with.
I have disassembled 4 or 5 J/L Ti-b's over the years, and have found that the epoxy type glue they use is resistant to every chemical I've tried; the only thing that I've found to work is heat, a lot of heat (industrial heat gun type heat).
Most of the units that I have taken apart were already dead, or otherwise broken, so the heat didn't damage anything that I was re-using.
That being said, a lot of care still needs to be taken so that the finish on the host is not damaged; I ended up making special tools to grip the host, and along with some leather for protection, it eventually came free.
There are some other internal threaded focusing pieces that may be glued also.
On a positive note, on the newer Ti-B's (520nm), the internals were modified to look a whole lot like what I did to modify my 532nm models, so that they would accept a standard 9mm lens holder. :yh:
There is a chance that none of this means anything in regard to your PL-E Pro, but I figured I'd throw it out there just in case. Good luck in your efforts! :beer:
Here is a -
LINK- to a Ti-B build thread I made quite a while ago that shows the internals, and disassembly of an old style (532nm) Ti-B.