I recently upgraded an instance of vRA from 7.2 to 7.5 and rather than do it the manual way I used VMware’s vRealize LifeCycle Manager (version 2.0 update 3).
Everything was going great and according to plan, the vRLCM pre-requisites checker made short work of all of the checks you need to do before you start an upgrade of vRA. You can see below vRLCM does a great job of keeping you informed of the current progress and in a really elegant way.