how to put bearings into a yoyo

how do you put bearings or make it able to accept bearings? Something like a duncan butterfly will used.

You would have to carve a bearing seat out, or something of that sort.

how could somebody go about doing that, just with some kind of tool thats in my toolbox

I believe it would require a lathe. Of, course I’m not that knowledgeable at all with modding.