CZealot,
If you can remove the standard non-ambi safety of the 75B, it will take you, oh, five more seconds to remove the the ambi safety.
With the hammer fully forward (and, preferably, with the hammer mainspring [#21] removed too), hold the ejector housing (#10) firmly in place and lift up the front of the sear spring (#12). While holding the spring up, remove the right safety (#63), then the left safety (#29).
That's it. The rest of the ejector assembly disassembles normally.
DL