Cargo Door Operates As Usual
Any search for RC-135 photos will probably show the fuselage cargo door opens as usual. The cheek fairing is attached to the door itself. There is a solid panel insert "weather door" with an approx. 36in sliding door, through which you enter.
If equipment needs to be removed/installed then the weather door panel can be removed.
The crew entry door is used for last minute entry, especially if the engines are running. Kept open, with ladder installed, until just prior to taxi.