Q.I Have A Birds Nest Fern That Has Way Overgrown It\\\’s Pot. It Seems Quite Healthy But Is Now Top Heavy!
How should I transplant it.

Certified GKH Gardening Expert
Looks like you need a taller container but not too much wider. These ferns are epiphytes, which means in their natural habitat, they attach themselves to trees or rocks to grow. So you may want to get creative with the container. The second article tells what to use for soil. It also says they should be repotted twice a year to keep up with growth.
https://www.gardeningknowhow.com/houseplants/birds-nest-fern/birds-nest-fern-care.htm
https://extension.uga.edu/publications/detail.html?number=B737&title=Growing%20Ferns#Variety
https://www.gardeningknowhow.com/houseplants/epiphytes/adaptations-of-epiphytes.htm
https://www.gardeningknowhow.com/houseplants/epiphytes/epiphyte-mounting-tips.htm