First you will need to dismantle old doors. They will need to be removed from the hinges and removed where they do not interfere. After that you have to install a door box and fix it. For reliable fixation, it is best to use special wedges, which are most often made with wooden. As soon as you install the wedges, the door frame will need to be leveled by the construction level. The same will need to be done vertically. If necessary, then the position of the door frame is adjusted according to the indications of the construction level.
