Brake light bolts

Hi,
Does anybody know how I can get the torx screws out of the rear brake/indicator light casings? I discovered the reverse lights and driver brake light and high brake light wasn't working, only the rear fogs and the passenger brake light is working, so I bought bulbs got home, replaced the reverse bulbs but can only undo 1 bolt in each light casing for the brake bulbs, the other bolt in each casing has been rounded by the previous owner

You can get stainless sets, which look better. You can then drill the heads off the rounded ones.

stig fasteners, got mine from them

Yeah I've already ordered some stainless on ebay from stigfasteners but I still need to get the old ones out and not having much luck so far. Might need to replace the passenger brake light fitting too as it looks like there is water inside, tho it does still work.