PART THREE - FLASHING THE FIRMWARE ON YOUR DRONE
To install the INMCAPPFw1.bin service file on your drone you must first format the MicroSD card while it’s in your drone camera (Zenmuse Z3 in my case, but the X3 camera will do fine).
Do not format the MicroSD card on your computer.
With the MicroSD card freshly formatted, copy the INMCAPPFw1.bin file on to the root (top level) of your MicroSD card. Ignore any other files or folders that may be there, leave them where they are.
Make sure the remote is switched off.
Now with the drone also powered off, insert the MicroSD card in to the camera.
This next part is important…
You MUST hold in the hidden Pairing button on the Inspire 1 - before powering on the drone.
Hold that pairing button in and while holding, then power on the drone. Keep holding that pairing button.
Only when you hear the camera bleeping this pattern:
D-D-D-D
{pause}D-D-D-D
Only then can you let go of that pairing button!
You have no idea how many firmware flashing attempts failed because I didn’t know this. The pairing button is required in order to force the firmware update.
Because we’re not rolling the firmware forwards or backwards, if you don’t force the update then you’ll get an error saying that the firmware is the same version and it will abort the update.
The all important pairing button is well and truly hidden on the Inspire 1. It’s behind the nosecone, right here (thanks for the pic, Droneland!):
Leave the drone alone now to install the update.
The updating bleep will change when complete. All the time the update is being installed it’ll sound like:
D-D-D-D
{pause}D-D-D-D
And when finished, that bleeping tune will change to:
DDDD-D-D
{pause}DDDD-D-D
Ie. A long bleep, followed by two short bleeps, followed by a pause.
You can now safely power off the drone.
Remove the MicroSD card and plug it back in to your computer.
You’ll see the firmware service file has been renamed from INMCAPPFw1.bin to INMCAPPFw1_updated.bin
You’ll also see there is a .log text file on the card now too called WM610_FC350Z_FW_RESULT_AB.txt
If you didn’t hold in the pairing button to force the firmware update, the log file will read something like:
Take a peek inside the log file.
You’ll see a bunch of stuff that wasn’t updated, that’s is fine. You’ll also see a few Result: Success messages in there too 
You must now delete the .bin file and the .txt file.
That’s it, you’re all done
Any questions? Just ask 