Need to fix a slow leak on a B2 swivel

[charlier]

My AA B2 2nd stage swivel has a slow leak. Although the reg is about 3 yrs old with about 450 dives, it has be trouble free, until now. I thought that I might as well fix it myself. I have never taken a B2 swivel apart, but looking at a blow-up, it seems that I should replace O-ring 20-2016-04, next to the swivel washer, O-ring 20-2017-00, located on the swivel housing, and O-ring 20-2013-01, on the inlet to the second stage. Is there something that I am forgetting? Should I replace the swivel washer while the hose assembly is apart. Suggestions are welcome.