White, D.A. Aderhold, S. Coy, R. Gonnella, D. JACoW Publishing Geneva, Switzerland 2673-5504 978-3-95450-234-9 10.18429/JACoW-SRF2023-MOPMB089 English 324-326 cryomodule vacuum hardware cavity MMI Contribution to a conference proceedings 2023 2023-09 https://doi.org/10.18429/JACoW-SRF2023-MOPMB089 https://jacow.org/srf2023/papers/mopmb089.pdf The Linac Coherent Light Source II (LCLS-II) super-conducting accelerator is fully installed and operational. Cryomodules were designed and manufactured by Fermi National Accelerator Laboratory (FNAL) and Thomas Jefferson National Laboratory (JLab) during 2017-2020. From November 2018 through March 2021, SLAC Na-tional Accelerator Laboratory installed 37 Cryomodules. Full system cooldown was completed in March 2022. Installation processes were optimized at SLAC for best quality, especially during particle-free and UHV assem-bly. These processes and successful Cavity and Cry-omodule manufacturing resulted in installed gradient exceeding design requirements by more than 20%. No statistical variation in field emission onsets or magni-tudes were observed between manufacturing and site testing. This paper summarizes SLAC experience during installation, and relevant testing results.