Hyang Zhao would probably be the best person to ask to. I don't have a MAC, so I don't know for sure, but MacOS X should have more or less the same tools as any other UNIX-like system. You'll need the 'bzcat' and 'patch' utilities, then unpack the official sources of the SL viewer, and apply all the patches in alphabetical order from within the source directory (with: bzcat patch_file_name | patch -p1 -s)
The commands used to compile the viewer under Linux are regrouped inside the
cmake-SL script, so you can get an idea of what commands to use by looking at it.
If you know exactly what you are doing, no, you don't need to apply all of them, but then you'll probably have to create your own AdjustRejects patch (this patch is applied last and is used to patch the lines that failed to be modified because the context around the lines in question was modified by another patch, resulting in a reject).
Just follow the links on the
website for the corresponding release. If you already compiled v1.23.4.0, then you already got the official viewer sources, and all you need are the patches available
here