Good on you for trying to figure it out before you have a problem. Since you can, pull the slide in half way so you can see where you need to hook up the extension. Hook it up and try to figure out if there is any way you would be able to do it with the slide all the way out. If the answer is no ..... start looking for some wood putty that will match the crown molding now. The only answer would be to pry the crown molding off and then reattach it with brad nails later. Hence the need for matching wood putty to fill the holes.
