Yeah they can be a real B* sometimes !
The platic piece is most likly going to break into a bunch of pieces.
The new filter will have the plastic part so thats not a big deal.
Where the red arrows are has to be squeezed down toward the filter then it will loosen up the inside catch.
You probly have road debrie in the fitting not letting it compress to release the catch.
See if tapping on it, or blowing it out helps....
... though watch your eyes!
Not to sound condescending ,
it's so easy a caveman could do it
