10-216 lower shower door guide

The 10-216 lower shower door guide. Once installed should they stay in place at opposite ends of the door? Do they need to be glued in place so they stay in place so the door slides on the track. My new pieces free float causing the door to tilt and not slide

It's hard to explain the installation of this guide, but I'll try. For the sake of discussion, imagine your shower door is lying flat on sawhorses, and that you've removed the two screws holding the bottom rail to the left and right stiles. Now, looking at the right hand corner of the door and holding one of the guides with the larger, flat-bottomed portion pointing to the left, slide the top of the right-most portion into the bottom of the bottom rail. When it's completely inserted, replace the frame screw at that corner. Your guide should then be attached securely beneath the bottom rail of the door, with the middle portion and the flat-bottomed portion not exactly "dangling", but able to be maneuvered outward, away from the door (if the door is on horses; downward if the door is vertical). Now hold the second guide with the flat-bottomed portion pointing to the right, and slide the top of the left-most portion into the bottom of the bottom rail, replacing the second frame screw to complete the operation. Then, after hanging the door's top rollers in the header track, use your thumb (or a flat tool) to "push" the flat-bottomed portion of each bottom guide into the slot in the sill track. You should hear it click into place. Do the same with the guide at the other end of the bottom rail. When you're done, you should be able to lift the door slightly and see that both ends of each guide have been captured by the bottom rail and sill track. The middle portions do little more than hold the assemblies together. To remove a door, insert the blade of a flat-head screwdriver between the sill track and the flat-bottomed portion of the guide. Then push downward on the screwdriver while twisting the blade to separate the guide from the track. It should pop out without too much trouble, but try to guard against the screwdriver blade gouging your sill track when the guide releases. How'd I learn all this? The hard way, of course. Good luck.