Window valance removal

[twowheelceu]

I own a 2013 Fourwinds 22E. The blind by the dining table has a broken string that I need to replace. The valance must be removed. The bottom bracket screws are no problem. But I can't locate how the valance is secured at the top. The valance is snug against the bottom of a cabinet. (see picture). There is nothing coming up inside of the cabinet. The blind has no snap brackets so it must be screwed into the valance. There are no visible brackets at the top of the valance. Help in figuring out how to remove this valance without making a mess would be appreciated.
Thanks.

[Yosemitebob]

My upper valance is secured with a screw from the top inside on each side. I use a 12" extenstion to get to it, but I have roll up shades and no blinds, so not sure yours is the same - there was no picture.