Hi Carol,
Wait until the pods dry, i.e turn tan color. They will split on their own and expose rows of thin black seeds. It may be a good idea to wrap each pod with a square of nylon to prevent bugs from tunneling through the pods and the rows of seeds. I don't know if this will work, but it's worth a try.
Good luck
:-)

I love Yucca too, especially the bluish green with curly threads and the green and yellow stripes.

Here is a link that might be useful: Yucca seeds