After marking the Aft Spar Flap Supports I pulled out my metal snips to trim the support as shown in Image 1. Image 2 shows me filing the cut edge with my Vixen File. Image 3 shows me using that same Vixen File in the holding tool I made (described in the horizontal stabilizer section) to finish the edges.
Using Metal Snips to Trim one of the Aft Spar Flap Supports
Using Vixen File to Finish the Trimmed Aft Spar Flap Support
Finishing the Edges of One of the Aileron Supports