If you pop the little cover off (the one that accesses the securing screw), there's access to one of the adjusters under it (up/down adjustment I think).
Once they're set, they shouldn't really need adjusting again.
Had my r/h unit out on Saturday to find out why it wasn't working.
bulb was fine, as was the fuse.
For nearly a year, the r/h Hi-Beam had flickered when the wipers were on, so I had an inkling what it was anyway.
The r/h wiper arm had been chafing away at one of the wires, so momentarily shorting with each pass of the arm, and had finally cut it right through.
The wires have a plastic shroud over them, but it had migrated slightly, enough to uncover the wires.
I had to unbolt the section that the lights are mounted in to get access to the damaged wire, then it was a simple job to splice a new piece in.
Luckily there was just enough length from where the loom comes through the bulkhead to do it.