Replace all important parts like shafts,bushings,bearings,sleeves,o-rings,gaskets and seals. After assembling check for vacuum seal. Leak test to 1*10-9 mbar l/s. Analyze the vibration and record the data digitally.
The booster will need to be replaced. First the brake pump will need to be unbolted from the booster. then the booster disconnected from the firewall and the peddle disconnected. Reverse instructions for reassembly.