A method for replacing a rotor blade on an integrally bladed rotor having a disk is provided, comprising the steps of: (a) removing a damaged rotor blade, leaving a stub portion of the rotor blade extending out from the disk, the stub portion of the rotor blade having a suction side and a pressure side; (b) providing a die, having a pressure side and a suction side, wherein each side includes a platform trough; (c) fastening the die to the rotor blade stub, with the pressure side of the die positioned on the pressure side of the stub, and the suction side of the die positioned on the suction side of the stub; (d) extruding a portion of the rotor blade stub into the platform troughs, thereby creating a platform; and (e) attaching a rotor blade to the platform.