When we recieved the A/C from the leasing company we deactivated the airstairs just by pulling the CBs, theres no need for a tech log entry to say they are deactivated as theres no point in cluttering up the maintenance records to cover an operational scenario. A note to the pilots and cabin crew that the airstairs were not to be used was all it took.
Sorry I have to disagree. If you carry out any work on any aircraft whether maintenance or operational you should always carry out an Techlog entry (or work card if its on pre-acceptance check)
There has to be some point of reference for the de-activation. You should also be doing it i.a.w some type of authorisation from your company tech or quality department which will refer to a specfic laid down procedure from Boeing (or similar).