Yes, I believe you do unbolt the pedal rod, pull it up into the cab, slide felt into its place and then run the pedal rod back thru the new felt's hole. If too thick, could you simply pull a couple layers worth of the material to decrease the thickness? If the width and or height is wrong, especially being too small, then that might be a bear to correct without getting another one.
Craig
My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear
My truck ....... Respect The Rust
If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.