How to repair and scrape the guide rail of machine tool

Is there any jitter? If the guide rail is worn, you can't scrape it. You can only use a guide rail mill and a big drag shovel. Remove everything on it, turn it over, wipe it clean, paint it with Indian red, and then grind it on the guide rail. Look at the points, the more the better. Use a custom white steel spatula. When shoveling, check the workbench to see its vertical and horizontal parallelism with the spindle. Only professionals can do it.