How to attach pin joint legs to ball joint crotch?

Posted in Custom Workstation

Here's a picture


They're Evangelion legs and they'll look great on the Marvel Legends custom I'm making, but I'm not sure the best way to attach. If I dremel into the leg to make ball joint hole, ill have to cut from the top of the leg so it can fit onto the crotch. I thought about using wire to wrap the ball and slide into the leg hole, then I guess clay around it, but don't know if that's dumb.

Anybody have any pertinent experience? Thanks a ton!