I use a fine toothed narrow kerf blade (I0″ 80 tooth carbide).

Clear the area of sawdust (flammables) and keep a CO2 extinguisher handy. The blade will heat up, so let it cool between cuts.

I lubricate it frequently with candle wax. The aluminum will melt and stick to the teeth and make slow nasty cuts and render the blade useless.

You’ll want neat clean accurate cuts. Recheck your measurements and clamp the extrusion firmly in place. You really don’t want to cut and trim as is sometimes preferable with wood.

I wear my best attenuators - it is horribly loud. Warn everyone to leave the room or protect themselves. They will appreciate the warning, and leave.