Hi John.
Ok, just to make absolutely sure - this is how DJI label left and right on the Inspire 1:
The arm is stamped in the “armpit” area with two circles, one blank and one with an L or R:
Of course the letter is closest to the interior of the aircraft but can be seen if you dangle it upside down
Please confirm that the arm you want is indeed an “L” and not an “R”
Easy to fit? - nothing is that easy on an Inspire. There are videos that help
Replacing boom only (the easier option in my view)
Replacing the arm entirely - All the videos I can find are timelapses without any commentary. You could examine them fraame by frame I suppose. This one is of a complete teardown and rebuild:
@PingSpike may be able to provide some insight if we’re lucky
There are also videos showing how to mend a broken boom with varying techniques - never tried them so not sure how effective they are. You can save your money and go that route if you think the repair will stand up to the stresses of flight.
As for payment if you decide to go ahead bank transfer or, at a pinch, PayPal would be the best options, PM me with your address and preferred payment method and I’ll give you the details.
Rob.