Subsea7 has recently installed the worlds first open source CCS pipeline on the Northern Lights project. A crucial part of the project preparations for using a carbon steel pipeline, lies in the pre-commissioning and the strategy for this. For Northern Lights the method has been developed together with Equinor. Complex terrain and length of route has been a factor in the overall method development influencing some of the activities. The focus for this presentation will be on how the pipeline was installed and necessary steps to prepare it for CO2 injection through various phases of the project.