There are 4 metal clips around the outside of the headlight unit.
Lever each clip off, carefull, these will ping off and hide under the sofa.
Remove the bulbs as found here. Heat up the outside of the unit where the clear lens joins the rear black housing. You can use a heat gun or put the headlight in the oven at a low temperature.
With the sealant heated up you can pull the lens away.
The interior reflector is screwed in in 2 places.
Look around the outside of the lamp for the 2 areas that the screws go into,
these are long plastic tubes as shown below.
With both Torx screws removed you can pull the reflector out.
You can now gain access to any part you require or even spray the reflector.
Reconstruction is the reverse of the above info. It is important you reheat the sealant before pushing the lens section back into the headlight back to be sure of a waterproof seal.