Fruity-ya-ya

I bought the r&g aeros with the hole cutter bit direct from r&g rather than digging out the right size from my Dads tool box.

Simple to fit with clear instructions which i read to check the torque after I'd cut the holes in the plastics and hand tightened them up.
Check you do not over tighten or you will be off to the shops for a replacement nut.

Other than that they were not needed, very intuitive.

Saying that I would stress that when marking the plastics make sure to fully tighten them back on as you go or the punch/marking tool will put more than one impression when you use it making it trickier than it need be when cutting (yep i had to refit and remark one side as i was a big head and didn't fasten it on first time - bit of tape to show me the true punch mark did the trick).

Although not needed, I also used a very small drill bit to pilot from the inside to out with a square of masking tape on the outside. I felt it helped stop the cutter from skipping (seemed to help anyway).

The awkward part was getting the bungs aligned as they are tear drop shaped. They spun in alternate directions as i tightened them straddling the tank. Would have been much quicker had i had someone to hold one as i did up the other but I might make myself a wooden prop for next time.