A financial services firm is upgrading their FlashArray//X70R2 to an //X70R4. The upgrade plan involves a chassis swap while keeping the original DirectFlash Modules (DFMs). During the pre-upgrade validation, the implementation specialist notes the existing array is running a Purity version that is not the required minimum for the R4 chassis. What is the correct sequence of operations to ensure a successful, non-disruptive upgrade?