Swapping from ADD drive flanges to Locking hubs can take 10 minutes or hours... Depending totally on the cone washers...
Some people smack the edge of the flange/hub where the washer is and it pops off, some like to get a small screwdriver in the split in the washer... Others go for the oxyacetylene torch after a few minutes....
There's some other hints in the FAQ here.
As far as swapping out the axle shafts, that can be an hour to days depending on the luck and approach. Pressing out the studs from the Diff flanges will make it a heck of a lot easier. Get a deep socket and a hefty c clamp, and have a propane torch handy, it may be the difference between easy and no go.