https://sourceforge.net/project/downloading.php?group_id=136478&use_mirror=mesh&filename=COLLADAMaya_0.8.2_bin.dmg&a=35507088it's strange because other versions of this same file wouldn't even install on my machine...
anyhow - after I did that, I just installed it, then in Maya I clicked on Window>Settings/Preferences>Plug-In Manager, and turned on MayaCollada plugin.
in order to know exactly which settings to use, this blog was helpful:
http://blog.papervision3d.org/2008/03/19/exporting-collada-from-maya-settings/
Tutorial to come...