First get the c-clips off or if factory melt nylon out.
Lay it in vice with the the ears of one yoke resting on the vice head on each side, don't even need to clamp down, just snug a little so it doesn't twist.
BFH and wack the yoke that's facing up. One or two hits is all it normally takes.
Pull caps and take out the one yoke. Flip 90 degrees so the cross of the u joint are resting on the vice tops, then wack the yoke that's now facing up.
Done.
Clean everything up. Take caps off the u joint, angle the cross in, then slide the caps in both ends trying to get the cross in each cap just a little bit for guidance.
Then slowly clamp with vice and draw caps in. Then get one cap punded in just far enough to get c clip on, then pound the other cap in.
Same thing for the other side.
It'd be much easier to show you in a 30 second video lol