Easy as pie, just take a chainsaw file and file in two grooves down the front aluminum spacer, don't forget to taper the land at the top between the grooves so feeding is clear. Be sure to test the bullet feeding to look for and clear obstructions.
I did this in about an hour or so years ago. I load my rounds out to 3.525" which gives me .050 clearance to the front of the mag.
Afterwards I spray painted it with flat black paint to give it that aesthetic professional look.