This is the skinning documentation written by Patchou, it can also be downloaded from inside Messenger Plus!. The CHM help file guides you trough everything you need to know to make a skin.

NOTICE for Internet Explorer 7 users: You may need to access the properties of the file and click "unlock" to see the content of the documentation properly. This is a problem caused by Internet Explorer security. You can also access the documentation directly from the preferences of Messenger Plus! where this problem doesn't happen.