Haven't been in the shop the last couple days LOL.
The extractor has flat sides. Just grip it on the sides, angle whatever you need to make the work space accessible - it doesn't take a ton of force to hold it while you file away the sides of the pad. I believe Steve used a dremel/power tool with a barrel sander/cutter that accounts for the rounded profile. I don't like power tools spinning at 5k on tiny parts so I just placed a small flat file at the 45 degree angle and cut until the desired flat topped pyramid was created. If the jaws make a little mark on the extractor just use some sandpaper to smooth.
The extractor has flat sides. Just grip it on the sides, angle whatever you need to make the work space accessible - it doesn't take a ton of force to hold it while you file away the sides of the pad. I believe Steve used a dremel/power tool with a barrel sander/cutter that accounts for the rounded profile. I don't like power tools spinning at 5k on tiny parts so I just placed a small flat file at the 45 degree angle and cut until the desired flat topped pyramid was created. If the jaws make a little mark on the extractor just use some sandpaper to smooth.