From my understanding, you are provided a concierge who stays on duty at all times you have castle access. The concierge MUST accompany you if you want to leave the suite after hours. Apparently they will call ahead to clear any maintenance workers in the area you want to visit, and are able to summon culinary staff, ride operators, and retail cashiers, although that may take a little bit of time from when the request was made.
The suite is the level above CRT. The windows are stained glass. The door is an unmarked wooden door, I believe its the first one on the right as you walk into the breezeway from the Main Street side. Behind that door is the concierge desk and an express elevator to the suite itself.