Oceniono na 5 z 5 możliwych gwiazdek

I don't understand how to do the Hack to get the add tab button at the right side of the tabs. "To move the New Tab button to the right side of the tab strip, you can use this userChrome hack:
.tabs-stack vbox hbox stack { -moz-box-ordinal-group:10!important; }
Please explain how to do this. Thanks

Ta opinia jest o wcześniejszej wersji dodatku (0.3). 

Hopefully this has been solved on MozillaZine!