This is definitely something the end user can do.

RCKen gave you the link to the info to do the software change.

If you need it, page 11 of the Flash 5X manual describes the mechanical changes for the elevator spring and throttle ratchet.
http://www.hitecrcd.com/Manuals/Radio/flash4-5.pdf
The drawing is pretty much identical to the one in the Optic manual.