I converted my old KB110 to hydro clutch. It was the single easiest part of the whole L20B conversion. I unbolted the brake master/booster, measured down from the top stud that holds the pedal to the firewall adjacent to the booster studs (on the engine bay side) and cut a hole with a holesaw for the rear part of the clutch M?C to poke through. Then I cut off the lower stud, and drilled a new hole at the correct center for the lower fixing hole on the M/C. Pushed a bolt though from the inside, and welded it to the indise of the pedal box to keep it in place/stop it turning while trying to do up the fixing nut. Then with the M/C bolted in, I lined up the clevis on the m/c pushrod with the clutch pedal. TBH, I cant remember if I drilled a hole through the clutch pedal to fit the clevis pin through, or if I made a bolt through the pedal boss, with a slight stand off to secuse the clevis to the side of the pedal. (it was ages ago) Either way, it's not overly difficult. BUT, the one thing you do need to be careful about is when you're cutting the hole with the holesaw, Be mindful of the return fold of the pedal box. The hole ends up very close to this fold that comes back away from the firewall. I nicked mine with the holesaw. If you're able to remove the pedal box, that would make that part easier, but I did mine with it still in the car.