Should I un-install the airports from the E: Drive before beginning with the install of the Add-on Manager to V4?
If you never installed into V4, the "standard" course of action would be reinstalling all of them (no need for uninstall, though), so the installer will have a chance to activate all the sceneries in V4. A reinstall wouldn't be needed in the future, in case you wanted to reinstall V4 again.
However, you might want to try a shortcut:
1) Install just the Stand-Alone Addon Manager, or just KCLT, in Prepar3D V4, which will add the software support to V4.
2) If you already have all your sceneries migrated under the new installation system (done when you installed KCLT in V3), you should have several Fsdreateam folders here:
Documents\Lockheed Martin\Prepar3d v3 Addons
Each one containing a folder for a scenery, which contains its own add-on.xml file. COPY all these folders
except the Fsdreamteam Addon Manager, from here:
Documents\Lockheed Martin\Prepar3d v3 Addons
to here.
Documents\Lockheed Martin\Prepar3d v4 Addons
Be very careful to copy ONLY the scenery folders, NOT the "Fsdreamteam Addon Manager" folder, because the folder in V3 loads the 32 bit version of the software, which won't work in V4, and you should already have the 64 bit version of the software, because you installed it in Step #1
3) Now start P3D and, if you did everything right, you should see a request from the sim to activate all the addons you copied. Reply YES to all of them, and you should be ready to go.
