How much can we customize jitsi?

Wonder if there will be legal issues if we remove jitsi logo to my owns all across jitsi-meet.

Is it that possible?

Look in the interface_config.js file for jitsi-meet. ( /usr/share/jitsi-meet/interface_config.js on my server )

There are many branding configuration variables to set or unset.

Yup I saw everything on all these files. But my questions is how far we can modify images or html content to adjust to our own?

if you run on your server you are only limited by the source code license - you can do about anything except claim you have an exclusive right on it , if you borrow the free meet.jit.si service you have to respect the terms of services