Cutting Vinyl does not require a mat . So if you need to move your rollers to use other material there is a blue/turquoise lever on the right side above the metal roller. Push that lever down and then you can move the white rollers by twisting and sliding them . They sort of snap into a grove in the metal roller bar and it is a tight fit . I used a little rubber needle gripper to hold the rollers while I turned them.
Be sure to push the blue/turquoise lever back up after you finish moving the white roller sections so the big metal roller is locked into place.
Another reason NOT to change the width of the white rollers when you are using paper that is "smaller" than 12" x 12" is the roller will try to ride over the sticky part of the mat and slip or advance at a crooked angle .
I learned this the hard way
I forgot to move the rollers back after I cut vinyl and the entire mat went wonky when I tried to cut an image from paper. I quickly paused the job and hit enter to back the mat out of the machine.
There is no adhesive on the very outer edges of the mat where the rollers advances the mat