FX Regulator screw Impact M4

I've managed to round off the regulator screw on my gun.

It's hard to believe FX made this adjustment screw out of brass. Hardened hex keys don't treat brass kindly!

I've been using a ball nosed hex screw driver to adjust it. I have to avoid the trigger when adjusting so the driver is always at an angle. This appears to be a recipe for disaster even though the popular tuning videos show it being done that way.

Top-Gun Airguns is sending me a replacement but I'm not looking forward to removing the trigger mechanism to get to it.

Has anyone replaced one of these... any help will be appreciated.