Changing labels - I think it's within $core_v2_ui

I'm just getting started with v11 and I'm trying to tweak a few things.  Some things I can find easily and work within the widget editor, other things elude me.

Here's what's currently eluding me:

Under "Group - Links", one of the default actions is "Bookmark this Group" (which toggles to "Unbookmark Group."

I'd like to change the language used here, but when I look at the widget in the editor, I'm seeing:

		#elseif ($link == 'groupFavorite')
			#if ($group && $core_v2_bookmark.SupportsBookmarks($core_v2_group.ContentTypeId) && $core_v2_bookmark.CanBookmark($group.ContentId, $core_v2_group.ContentTypeId) && $core_v2_bookmark.CanUnBookmark($group.ContentId, $core_v2_group.ContentTypeId))
				<li class="navigation-list-item">$core_v2_ui.Bookmark($group.ContentId, $core_v2_group.ContentTypeId)</li>
				#set($hasLinks = true)
			#end

From the surrounding code, I think I'm in the correct space, but I can't figure out how to access the contents of the (or even just change the labels) within the Bookmark function or the parent information contained within core_v2_ui.  I might be barking up the wrong tree, and if that's the case, I'm hoping someone could throw me a bone.