I have a Dell-refurbished XPS 15 with a hybrid drive and want to replace it with an SSD. What are the procedures for doing this? For example, I heard that hybrid drives are installed with RAID mode so I should install my SSD in AHCI mode?
It depends - are you planning to install a 2.5" SSD or an M.2 NVMe drive?
Make a set of recovery media if you're planning the latter - you will need it to load the OS on the NVMe drive.