Didn't see a guide for this and although it was easy, I figured a video might help some
Nice first post and video guide!
One thing to mention is that there are several key parts that run through the side sill/rocker panel where someone may drill (cooling pipes, wiring etc.). Julian73 first pointed this out in '14 and warned everyone about.... "the main body wiring harness routed along the LHS (Driver side on US cars) rocker panel is mounted flush to the lower body". So, when drilling blindly into the rocker panel, it would seem that using a drill stop while drilling would be a very prudent move. Although, each car could be slightly different so drilling that area may or may not be an issue.
Please see thread:
*** INSTALLATION WARNING *** While this doesn't seem to be a common issue with installation, I found on my car an early MY12 that the main body wiring harness routed along the LHS (Driver side on US cars) rocker panel is mounted flush to the lower body. In the region under the door location...www.lotustalk.com
Of course, I do not know if GRP's mounting holes are in the exact same location as say HK Fever's barge boards, or even the original Lotus barge boards. But, I would assume they are in a similar location and thus require similarly positioned holes.
Anyway, welcome to the forum!!