TargetFrame SetTextCoords

[sirpucna]

i'm looking for a demonstration on how to cut out a portion of the PlayerFrame/TargetFrame with SetTextCoords as show here:


My intent is to use blizzards texture and not use a custom one to create thick health bar, but doing so without it being obvious(green highlighted square to cut and paste the part below it)

I've seen it done with a addon called Baik UnitFrame Module, but its complexity is far beyond my skills.