There are several ways of attaching the Cinemilled plate to the Black arms base plate. You can either use two screws or four. The Cinemilled plate is longer on one side, and blocks two of the screws attached to the rods, but there is a easy way to access those. Depending on if you are a multi gimbal facility or a Ronin only (The Universal Cinemilled plate will work both for the Ronin and the Ronin-MX btw, so you can use the same plate, according to the info we got from both Cinemilled and DJI). You will use one of the following options, one quicker and one more rigid.
Note: Always use loctite or similar mild/medium thread glue at all times. There is an incredible amount of vibrations once on the road, and a screw might get un-winded in no time. Make sure to use threading glue on the Cinemilled plate screw! That ones will be the weakest point in the chain (do not use permanent/strong thread glue though!).