Removing that little 'lip' on the right of the extrusion?
Router with a pattern cutting bit. Carbide bit. Full PPE. Some sort of jig/fixture to hold the aluminum so that your fingers are AWAY from the bit/blade.
A tablesaw with a carbide blade (a blade made for cutting aluminum would be best, but a 'standard' general purpose carbide blade will cut the aluminum) can work. Again, full PPE and rig up a jig/fixture to hold the aluminum so that your hands are AWAY from the blade. You will have aluminum chips EVERYWHERE afterwards. Go easy on the feed rate and let the blade cut and don't force the cut. Nope on installing a blade backwards.
Or sand the little lip off. Belt sander, angle grinder with a flap disc, random orbit sander, etc.
Or you can use a sharp chisel and pare off the lip. Probably have to resharpen the chisel afterwards.
A file (get a file made for use on aluminum and coat the teeth with chalk before and during use) will make pretty quick work on a few pieces of aluminum.
Full Garage Journal mode: You will need to go buy a milling machine.
