For Firefox User:

1. Install the free Firefox Add On Stylish: addons.mozilla.org/de/firefox/addon/2108/
   
   
2. Close Firefox and reopen it.
   
   
3. Now you should see this Picture on the right side:
   
   
4. Klick on it, afterwards klick on "Create Skin" and then "New Skin". Now it should look like this
   
   
5. Copy the Code of a Stylish Skin (you can find those in the Skin Section)
   It should look like this (just a lot longer):
   

   Source Code

   1. @namespace url(http://www.w3.org/1999/xhtml);
   3. @-moz-document
   4. domain("andromeda.ogame.it"),
   5. domain("uni1.ogame.it") {
   8. ...
   
   
6. Now fill this Code in the Stile Window you've opened (4)
   
   
   
7. You're almost done! Just give the Skin a Name of your choice and save it
   

If everything works fine, you should already see the changes. If you can't, then probably the Skin isn't working any more. Try another one and ask us if you can't solve the problem.

Further Informations:
Stylish Website: userstyles.org/
Stylish Forum: forum.userstyles.org/

Video