A method of replacing the root part from a wind turbine blade by attaching a new fabricated root part consisting of utilizing a new root part manufactured specifically for the blade to be repaired, which does not use the same materials as the original. To separate the original root segment from the original blade the cut line with single or double bevels is prepared, both in the new, pre-fabricated root assembly and in the region to be cut of the original blade. The next step is joining the new root assembly with the original blade using layers of structural fiber fabric, initially utilizing reconstruction layers and subsequently with internal and external reinforcement layers on the blade and, optionally, apply resin preferably through vacuum infusion and optionally through hand layup, to complete the joint between the new root and the original blade.