Rear brake adjustment

On my little ride out I'd had real difficulty applying the rear brake whislt standing. I could barely feel the pedal, never mind tilt my ankle enough to apply it.

In the manual an adjustment of pedal height is shown via a locked screw inboard of the lever. How can you get to it?! I removed the return spring and brake lever and turned the screw (lock nut is 8mm WAF) in to lift the pedal. I was aiming to have it level with the footpeg. However this removed the piston actuator from the cylinder, so miles of free play. The actuator then needed adjustment. The lock nut (10mm WAF) was fine but the actuator needed a bit of persuasion with penetrating oil to unscrew. It was screwed fully home. I took it out, wirebrushed it, placed copperslip and replaced it about 5mm higher than before. With a trial assembly I felt I'd achieved a higher pedal, with just 5mm of play, as suggested in the manual. Fresh copperslip and grease on the pivot and it could all go together. To be tested...