Removing Virtual Yoke

I am having some problems doing this, and I was wondering if someone could help me. I did manage to do it once before, but now when I try, I only end up with a partially gray panel and the yoke is still there in silver gray. I am using DXTBMP, and here are the steps that I have followed.DXTBMP-Load extended image(also tried as normal image),Prefs-select editor-MSPaint,Image-Send to editor-MSPaint,MSPaint-Painted over the yoke with black(also tried with pure green),Saved the file and exited MSPaint,DXTBMP-loaded the extended/normal image(tried both),Alpha-Create black/green alpha chanel(tried both),Saved extended bitmap-The file name was saved as the original fs9 file name. FS9-Copied extended bitmap file to the texture file of the aircraft. I just can't figure out what I'm doing wrong. Any help would be greatly appreciated!