Check ZPOST in the e89 section under the engine trans, exhaust modification file. User name z4z4z4 just did the rears on a 2011 e89 Z4. He as a detailed description and photos. There was no description of a computer reset of the e-brake motor. He just removed the motor and turned the piston 15 turns to it start position. He seemed very happy everything is working.
2014 BMC Z4 35i, 6 Speed MT, Deep Sea Blue Metallic, Black Kansas Leather, M sport Pkg, Cold Weather Pkg, Premium Sound Pkg, Technology Pkg, Park Distance Control