I recently took on the same project and can say it isn’t the easiest but you can do it if your so inclined with the right tools and patience. Procedure is as follows:
Drill out old 510 with a bit just slightly smaller than the outside diameter of the current 510.
Use a smaller dremel grinding wheel or grinding stone attachment to grind out a spot in one of the walls of the remaining brass 510 insert. Be careful not to go into the aluminum behind the brass around the top edge otherwise you’ll be able to see it when you replace the new connector. Cutting into it a little below the top edge isn’t a big deal as you won’t see that at all with the new 510.
Gently pry or pull the old remaining brass insert out with needle nose pliers or a flat heat screwdriver.
Clean out opening in the aluminum making sure all brass pieces are removed and no dirt or dust is leftover in it. I suggest washing the entire
mod under running water with some dawn dish soap and some pipe cleaners or straw cleaning brushes.
Align new 510 perfectly with the current hole and press in using arbor or other press. I also used a socket aligned with the current 510 to push it all the way down. I suggest something the edge the press or socket touches to prevent damage to the new stainless 510. Mine got some marks on it but I was using a 6 ton press and don’t think I aligned it perfectly at first so it took a little more persuasion than it probably needed.
That’s about it besides setting up the rest of the new parts. Which I can also write out if needed.
