PULL OUT OLD STRIP...clean the channel with some alkeyhol make sure you get all the old adhisive out of channel. you can filp over the one you pulled out....IN AN EMERGENCY.... and reset it into channel.
or you can buy a new one from ROLANDS PARTS DEPT.
all the rolands from PNC-1000 to CX-*** all are bout the same and will fit the channel.
i am not familiar with that particular model, however many many moons ago i had a pnc 1860 and what i would do is slowly pull up the cutting strip trying to remove as much of the glue as possible with the strip, i found if i yanked it out quickly more of the glue strip would be left behind...then i would use just enough adhesive remover in the space that the strip was to remove any dirt and left over adhesive...and let it dry totally then simply place the new strip in place and apply firm pressure to adhere... i know that pacific coast sign supply (pacific coast paint) has a amazing selection of parts http://pacificcoastsignsupply.com/