Porch Pillars

I am trying to replace wood that has rotted.
Basically, I want to figure out if the pillars are load bearing.
At first look, it seems like the pillars have to be load bearing as the porch roof juts out from the house.

However, the construction of pillars makes me think they are perhaps not load bearing. Please see photos.

They are essentially a box (front+back+side+side) of thin, non-treated lumber.
I would like to just cut them at the bottom, and replace the rotten wood.

Any thoughts on whether these are load bearing or what to do?
I don't want to make a costly mistake.