Upon arrival I was greeted at the front door by the homeowner and led into the guest bathroom where I had previously quoted her to replace the failed Hans grohe shower cartridge. Upon receiving authorization I promptly shut off the water at the main valve located on the east side of the house, I then went back inside and drained the system using the bathroom faucet. I then removed the shower trim and removed the failed shower cartridge. I then prepped the new cartridge by putting plumbers grease in the i rings and installing the cartridge nut using the clip off the old cartridge. I then installed the new cartridge and then the shower trim. I went outside and turned the water back on at the min valve and tested the shower for proper functionality. It works perfectly.