Just installed ours myself.  Instructions aren't very good but I know enough.  Had to cut the drywall on the backside of the shower to gain access to the old shower controls. I cut the supply lines, removed the old shower system and then used 90 degree sharkbite connectors to complete the hookup. Installation took about two hours total but that included the discovery operations to see what my existing system had.  A little bit of drywall work and it will look like new. My wife and I have both used it since installation and are very impressed with the water pressure and features.  Nice upgrade for minimal time and money!