Making Square Columns Round (w/ comments)

My house is NOT in a historical zone…
I have four 8 ft square wood columns that are covered with EIFS (stucco-like product). The columns are 2 per side of the house entrance with a small roof/cornice on top. I want to make the columns round.
How to make the columns round??:
1) Replace the columns with round ones – requires jacking up each column during swap out, etc.
2) Remove the EIFS to the bare wood.
Sand the square shape into a circle
3) Create a circular cast and then build out the square shape using some type of synthetic hardening product.
Has anyone ever tackled something like this? I guess a master carpenter could help with choices 2 and 3… Any recommendations greatly appreciated!!