Help please with a panel edit

I'm wanting to substitute the default FCU in the Grabowski ERJ panel with the vasFMC FCU. So far, I have not had any problems adding vasFMC PFD and ND to the panel - and it looks good so far. I was able to add the vasFMC FCU gauge to the basic panel window, but I had to add it on top of the existing FCU. The new FCU covers the default FCU just fine and it works, however, when I turn on the panel lights I get some flickering of the default panel lights under my added FCU gauge. Because the default FCU is part of the main panel, I cannot just substitute gauges. What I'd like to do is "blackout" or cut out the portion of the panel under the glareshield containing the FCU (if that is possible). I realize that is not the same as removing the default gauge, but I am hoping that would hide the flickering I mentioned above. Then I can just add the vasFMC FCU gauge but just place it on top of the area I black out or cut. Does this make sense to do and will it fix my problem? Can I do this using MS Paint or is there a freeware pain program that would be better? I have a sneaking suspicion it's not that easy!I suppose another option is to just create an FCU pop-up window that will be placed over the existing FCU, but I'd like to try the above plan first.Thanks for everyone's help.Todd