On this evenings agenda was filing down the rear seat lap belt attachment points in order to allow access to the flap bearing brace’s rear bolt. I used a thin socket to roughly mark the area to be removed. Left side shown. 

I started by using the dremel with a small sanding attachment. The location makes the going slow and difficult. You can see the first pass here.   

This was enough to allow access to the socket.  

Here is the right side after the first pass. 

I cleaned the areas up with small files, sand paper, and finally scotchbrite pads. It was slow going, but I’m happy with the end result.