I need to replace the low beam bulb but, cannot figure out how to get the grey dust cap off to access. It’s tight enough getting in there and can twist it a bit, but afraid to pry to much and break it.

any ideas on how to change that bulb?

 

A little Penetrating\SiliconeOil around DustCap seal\seat, let set a few minutes,
then try again with ChannelLock\ViceGrip Pliers.
A little more Oil on Seal\Seat before you put back on.