The CMS Muon Spectrometer is being upgraded (the GE1/1 project) during the LS2 shutdown (2019-2020) using large-area, trapezoidal-shaped triple-GEM detectors in the forward region, 1.6 < eta < 2.2. We present the chamber assembly and qualification procedure, as well as an overview of the results obtained during detector qualification. We report preliminary results on system integration and tests of the production version of the chambers with their digital electronics. Results from the pre-production chambers installed during 2017-2018 (Slice Test) are presented together with details of the detector control system. Slice Test results are presented on front-end electronic channel loss and a solution to mitigate the problem. We present an overview and recent results on classical aging studies and longevity tests and their impact for the use of triple-GEM detector systems in CMS.