how to add motorized wheels to a lawn mower

Hi everyone, I am working on an autonomous lawn mower project and trying to figure out how to choose motorized wheels to replace existing ones in a lawn mower.

I am thinking about hub motor wheel in skid-steer configuration. What are the tradeoffs that I need to pay attention to?

Where should I look for a motor?

And how do I go about actually replacing the wheels, what tools do I need?

And how difficult is this task?