HOW CAN I FIX MY XBOX ONE DISC READER, IT TENDS TO REJECT THE CD; WHEN I CHANGE THE CD IT SOMETIMES SHOTS THE CD BACK OUT OR IT SAYS "DISC IS NOT READABLE PLEASE INSERT A XBOX ONE DISC OR COMPATIBLE DISC"

First Step would be to try a CD Leans Cleaner , you can buy them from music stores & local Shopping center , they are simply a cd you put in , they run for a few moments cleaning your cd laser lens inside machine , the cd has a little brush on disk , which may come with a liquid that you put one drop on little brush part before inserting it, if problems persist, try putting Xbox on its side or different positions, if this helps , then your laser needs adjustment , this will be a more involved procedure, mostly done by a tech, make sure roaches are not breeding inside it, this is a common issue for some, check disk/game for marks or dirt etc, .