i dont know but its either clipped on or its got that black foam glue strip can only sujest to try pry it gently from underneath from one side see if it comes out a little then move up a bit try pry a bit more little at a time
i had a look at it again, found my long skinny screw driver and gently pried them off. they both came off in one piece without damage, slight bend to them afterwards but easily bent back into the correct shape and fit back perfectly.
they are glued on with black polyurethane with 2 locating pins.
they are not plastic they are alloy as well. i always thought they were plastic.