Jottle

I bought a set of racing pedals here on the forums years and years ago, and my set just has the three pedals without any shims for the dead pedal and brake pedal. My question is regarding the install procedure for the brake pedal on my 06' A/T. The instructions say to install the brake pedal by removing the rubber from the oem brake pedal and using the included shim. My set didn't come with any shims. I'm assuming I just install my race pedal by drilling through the oem rubber and metal brake pedal just like I did for the accelerator and dead pedal? I read on the installation thread that there's a cavity in the brake pedal if I remove the oem rubber and install the pedal without it. Is it the correct way to install the racing brake pedal (w/out the shim) by drilling through the oem rubber and metal? I can't see another way of getting this to work short of filling the cavity in the middle with some rubber.

Side note: Did they just stop making shims for these in the later sets? I got mine from excelerate.