Hi gerry,
Welcome to the Heartland Owners Forum and Family. I'm sure you will meet lots of great people and get lots of good information.
Go to this thread and check post #7. I think you will find a pdf file there for adjusting slides. If your not to far from your dealer, I would suggest you let them do it. //heartlandowners.org/showthread.php?t=10102&highlight=slide+adjust
Jim M