All the menu icons used by Alpha are stored in Apple Icon Image format
(files with a icns extension). These files are located inside the
application bundle.
Customizing the menu icons is very easy. When Alpha needs to find an icon,
it looks in several places in this order :
The first icon found is selected. So, in order to change an icon defined in
the bundle, all you have to do is to install your icon in the user's (or
local) Application Support folder and make sure you give it exactly the
same name as the icon it replaces.
Here is an example with step by step instructions. Suppose you want to
customize the OzTeX icon which you chose as your LaTeX menu icon. The corresponding icon file
is named oztex.icns :
open the user's (or local) Application Support folder ;
if there is no folder named Icons in it, create one now ;
copy your new icon to the Icons folder ;
rename the icon as oztex.icns.
That's all there is to it. Next time you launch Alpha, it will pick the
icon you just installed instead of the one located inside the bundle.
A subsidiary question is "how do I know the name of the icon file ?".
This can be done by inspection inside the application bundle. The
icons are located in Alpha.app/Contents/Resources/Icons.
Alternatively, if you have a working copy of the Alpha sources (see
QA #1), the icons are found in
Current/Core/Resources/Images/Icons.