You could just sand it with your hands, but there is a large chance you won’t do it evenly across the yoyo which may make it develop vibe. The machine just helps with accuracy.
what you do for the drill is take out the drill bit, put the yoyo in by the axle (it may do a little damage to the axle, so i recommend either having a replacement axle or taping it) when you spin the drill, it should spin the yoyo. you want a fair amount of torque. you will need some lower grid (600) and some higher grit (1000). use the lower first and then go to a higher grit. after that, it is a matter of polishing.
yeah it took me a few hours with sand paper and it does great my eight has a lil wobble but its from where i some how messed up the thread inside the yoyo