Sentence:  If locomotive is to be shipped on its own wheels, remove motor brushes or have locomotive <WSD>degeared</WSD>, and set brake-cylinder safety valve at from 25 to 30 lb opening pressure, tagging the valve with the opening pressure, and open the dead-engine cock. 
Meaning of the word marked with <WSD> tags:  To remove or disable the gears (transmission or interlocking gears).