David, First sorry for the delay, I'm at the Monterey Shootout at the moment, so I am not as quick as usual (as not in front of my desktop all the time )
Your bulkhead are have a retaining O-ring inside, just diconnect from the switch board, remove the O-ring and pop it out, replace with the Optical and after you do an immersion test (to confirm how good you are at doing this!!! ) the you are ready.
I am back at the office wednesday morning, if there is anything else I can do more let me know.
BTW its a great event and yesterday's presentation was a gala of nice images including some of our own wtpixel member Eric Cheng and Stephen Frink. t<was a nice evening.
Cool! Thank you, I'll give it a try.
(Wishing I was in Monterey ...)