"wit extract image workingdir" will extract all files to the local file system.
"wit copy workingdir newimage.iso" will create a new image of the and perhaps modified files.
Instead of "newimage.iso" you can write newimage.wdf or newimage.wbfs to copy to another format.
"wwt add --auto workingdir" will direkt add it to a wbfs. Option --id=id6 wil change the ID of the game.