Here is how to configure it to fully work in P3D v2.5:
Install it normally, or just copy all the Captain Sim directories from FSX folder to P3D.
Then after this go to your directory X:\Users\yourwindowsaccount\AppData\Roaming\Lockheed Martin\Prepar3D v2\
there you will find this file called dll.xml, open it with notepad and admin rights and in its end lines add the next code before this code line </SimBase.Document> click save,  then almost everything should work, here the bleed air unit and ground power unit wont work.      
  <Launch.Addon>
           <Name>Captain Sim 767 Menu</Name>
           <Disabled>False</Disabled>
           <Path>Captain_Sim\Captain_Sim.b767.menu.dll</Path>
     </Launch.Addon>
Your installation must be registered in your windows register.

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