Download the Mindstar specific Add-on from the link below.
Extract and copy this to the same P3D Add-Ons folder.
C:\Users\UserName\Documents\Prepar3D v3 Add-ons
After installation, your Add-Ons folder should look like this
After you extracted the RealSimGear folder per above, you DO NOT need to run the RealSimGear.exe file, when you start P3D, it will run that file.
Go ahead and load up P3D, on the first run, you should get 2-3 prompts about RealSimGear, 1) asking if its OK to load the RealSimGear Add-on, 2) may be a security type prompt asking if you trust the RealSimGear, and 3) a prompt asking you to remember RealSimGear for future. You should accept or say yes to all 3 prompts.
Once P3D loads, go ahead and load an aircraft. When it loads, you should now have an Add-on menu in the top menu bar. Select that and there will be a RealSimGear entry. Select that entry which should open up the Connected Device window and you should see entries there corresponding to the RealSimGear hardware you are working with.
Update the Mindstar Configuration File
Note, for use with Mindstar there are some changes required to the Mindstar configuration files. Locate the GNS.ini file, which is in the following folder
C:\Program Files (x86)\Mindstar\Flight Simulator Addons
Copy and paste the lines below into the GNS.ini file, overwriting the "GPS1_....." lines that are already there in the [KEYBOARD] section. Ensure that 'USE_DEFAULT_EVENTS=NO'.
Save the GNS.ini file
Note, the above instructions cover only the GNS530 product, please contact us for details on the configuration for the GNS430 or G1000 product.