Q.How to Trim a Yucca Plant
Do I trim to where the trunk grows without the leaves, like a tree?

Certified GKH Gardening Expert
It depends on what you want to accomplish with pruning. The part of the trunk that does not have leaves will not regrow leaves if you prune the leafed part away, but it will often sprout new branches. You should leave at least a few leaves on the plant if this is your intention to make sure the plant can still produce energy.
This article may also be helpful:
https://www.gardeningknowhow.com/ornamental/foliage/yucca/yucca-plants-care-and-pruning-tips-for-pruning-a-yucca.htm