"Well you pretty much named the essential steps:
* remove upper and lower shell
* remove LED-cover (pry loose carefully) and cable clips
* remove motor bolts
* take a photo of the motor wires at the ESC board (to remember when re-soldering)
*…"

"Iris is not made for 4S Batteries with 14.8 V but only for 3S with 11.1V. The normal calibration will probably not work.
AFAIR the IRIS will normally not toast itself due to the high voltage, but the gimbal electronics might ....

         Good luck…"

"What about re-soldering wires?

I just re-connected the rest of flex-cable that was still on the LED. Be aware that the shrinkwrap-part contains a resistor limiting current through the LED.
You need to scratch some new solder pad into the flex-cable…"

"www.amazon.com/gp/aw/d/B00JVOEWB4/ref=redir_mdp_mobile/175-4473986-...

You have seen those?"

"No experience here but:
According to XCopterCalc it would probably help to fit props as large as possible. That gets you more lift and better (lower) RPM in thin air. Theoretically with 11 x 4.7 props you are back to hover @ 60% throttle.

One mod…"

"The 20C means a current factor: the maximal current to be drawn from the battery, based on the capacity.
5.1Ah * 8C  = 48 A
2.2Ah * 20C = 44 A
The Phantom Batteries would probably work, but only for a short flight as they have less than half the…"

"The LEDs are connected to the main battery power by normal wires. There is a resistor inside shrinkwrap, and then another solderpoint to the flex-cable of the LED. This all seems a bit brittle. I had to repair this after a crash."