Just wondering if anyone has had a go at changing the diff gears themselves and how hard was it to do? I know how to set backlash and preload but the part i'm interested in is actually how hard it is to get the centre and ring gear out of the diff and back in and how hard to get the pinion out (i assume that bolt holding it on is a tad tight?)
edit: this is for an EA bw diff.

I just put 4.11s in my eb falcon and i had a go my self, then ended up getting some pros to do it, here are some of the things i learnt:
I have an EB series 2 wich has a bigger diff and 28 spline axles, the 4.11s are out of a pintara which has a smaller diff housing size and a smaller bearing. I think the pintara diff housing is the same as the EA diff housing. The crown wheel (ring gear) is pretty easy to get off, just use a rattle gun and remember its left hand thread. once all bolts are undone hit from the back with a hammer alternating around the gear. and the pinion gear needs either a really big breaker bar or a rattle gun also. When you pop the center out and put it back in DO NOT hit the shims with a hammer, use a piece of wood or something, they break pretty easily.

What ratios are you putting in? I just bought another set of 4.11s that i am not using any more they are for sale if interested.

I'm only going for 3.45'. up from the 3.08 i have now.
So what was it exactly that made you give up and get a pro to do it? Sounded like you got pretty far into it.

Yeah i did the complete install but the problems i had were related to the diff size difference. I put the gears in and still had lots of slap between the pinion gear and the crown wheel. Thats when i sent it to a proffessional to get rid of that slap. even after that tho the gears were still noisey. I think this is because There may need to be a shim between the pinion gear and the bearing for the kind of conversion that I was doing.
Your case is different tho. What year is your diff housing? if the diff is the same size then the conversion will be relatively simple. I think from EBII onward and some earlier v8's have the larger housing. earlier than that may have a different housing. This isn't too much of a hassle if you take the pinions to a diff person they will be able to swap the bearings over and that should be sweet (assuming that no shimming is needed like in my case).