i used some masking tape to mark where the cut would need to be, masked the whole hump to prevent scratches.
Unmasked the area and needed to be grinded off, use the bar to check for thickness (the cut should be just about the same height of the side of the grab bar).
Used a dremel with rotary grind tool... finished it with a smaller blade for the edges, then sanding it down.
Take your time or the paint will chip (hence the masking tape here).
Also test fit it plenty and you should be golden!