relax, if its the FRP I know, there will be PVC pipe and instructions included. even a dealer can 'figger it out. The spring rate you mention resembles a rear spring, not fork.
Do you ask only to tell he dealer what to do? :) That works... :think:
What's the chances of the dealer putting back in your stock spacers or cutting the PVC with a hacksaw, creating an annoying click on every stroke? pretty good imo.
Unless you know your shop well, they may give this job to the kid sweeping floors for the summer. :(