1.Intall py2deb on n900 2. in MyDocs make a folder to the theme ex harmattan-black (is not going to be theme name) 3. and then you must make folders like this in the folder you created in MyDocs. /src/usr/share/theme/Harmattan-theme-black In Harmattan-theme-black you put your theme files. 4.Then you must make a mybuild.py Here you have mine from harmattan white http://dl.dropbox.com/u/15968404/build_harmattan.py Change version number, changelog, maintanier, pacakge name and more.. And put the icon (64x64) and mybuild.py under /MyDocs/harmattan-black 5 the open terminal and type root cd /home/user/MyDocs/harmattan-black python nameofmybuildfile.py And wait 1-2min den you must press enter, it will be on display when you press. And then you have the files under /MyDocs/harmattan-black 6. https://garage.maemo.org/extras-assistant/ And there you upload to extras-devel