1990 Spirit. Door sill chrome trim removal

I would like to remove the chrome *sill* that sits at the top of the
door, so that I can replace the plastic moulding that resides
underneath.

It looks like the sill is held in place with screws. It it appears that
these the screws are not accessible regardless of whether the window is
in the up or down position.

Does the glass need to be removed in order to gain access to the
screws? Has anyone ever taken one of these apart, and may have some
tips on how to do it?

Thanks,

Kirk Matheson