The present invention provides a guide tool adapted for removal of damage cartilage and bone and adapted for guiding insert tools during repair of diseased cartilage at an articulating surface of a joint, wherein the guide tool comprising a guide base having a positioning body and a guide body protruding for said guide base characterized in that the guide body comprises a height adjustment device and a guide channel with a length and wherein the guide channel extends throughout the guide body and through the height adjustment device with one opening on a cartilage contact surface of the positioning body and one opening on the top of the height adjustment device and wherein the guide body comprises a height adjustment device being arranged to enable stepwise adjustment of said length
