I have a front porch covering with four round roman like columns, that looks like this:

We want to change them from round to square, something I would like to tackle myself or at least understand how it should be done so I am educated a bit.
Here is how they are at the bottom:

...and top:

it looks as if the footings on top of the bricks are 2x12s cut square, and then the column trim sits around the column and on those 2x12s to shed water. There are also screws/nails (can't tell because of paint) that fasten the trim/columns too. The columns are some lightweight metal or fiberglass something.
one thought would be to just leave everything as is, and wrap what is there with 1xSomethings. The larger size of the new square columns might make the spacing and proportions looks a bit whacked though...
Any one know how to remove the round casings? Is it a matter of simply cutting all the metal column and trim and exposing the post underneath, so do they disassemble someway?
Assuming I am going to find what type of posts under there? PT wood, metal, 4x4, 6x6?
Any insight would be appreciated...

We want to change them from round to square, something I would like to tackle myself or at least understand how it should be done so I am educated a bit.
Here is how they are at the bottom:

...and top:

it looks as if the footings on top of the bricks are 2x12s cut square, and then the column trim sits around the column and on those 2x12s to shed water. There are also screws/nails (can't tell because of paint) that fasten the trim/columns too. The columns are some lightweight metal or fiberglass something.
one thought would be to just leave everything as is, and wrap what is there with 1xSomethings. The larger size of the new square columns might make the spacing and proportions looks a bit whacked though...
Any one know how to remove the round casings? Is it a matter of simply cutting all the metal column and trim and exposing the post underneath, so do they disassemble someway?
Assuming I am going to find what type of posts under there? PT wood, metal, 4x4, 6x6?
Any insight would be appreciated...