How do you clean gas burners for XL 1100 Trane furnace? Also I read where the flame rollout switch showing open is symptomatic of a furnace drafting problem. Exactly what does that mean?

The roll out switch will tell you that you might have a blockage in your vent pipes. Also tells you the heat exchanger might be bad. Take a look at the flames and see if they are "dancing" or steady.