They are a poor design. Such a simple part rarely just snaps on with out breaking at least one tab. I have seen where you need go though a bunch of hoops to hold one side of the esc tucked up into the cover while at the same time pressing the other side in place. Its just not worth the trouble of installing. And as said above, you will be replacing motor mounts pretty regular any way, so its hardly worth the trouble. I got to the point of just snapping off the tabs from the start, and using black zip ties which you can cut off easily for those crash repairs your going to have.