Well, I feel like I really made a mistake now... Sorry F2thaK.

Santicorcho, there is really nothing we can explain better than in the first post. Everything is detailed and accurate. I'll try to re-detail the steps below, but don't expect me to provide further support. I'm not even skilled enough to provide any support, actually.

1. Using you computer, just extract all the stuff in this file in the root directory showing up when the N9 is connected to the computer in Mass storage mode (actually corresponding to /home/user/MyDocs in the N9 filesystem, but nevermind).

2. Open terminal on the N9. Type "devel-su", then "rootme", then "sh /home/user/MyDocs/FT-install.sh". The command line is case sensitive, so don't forget the caps in the ".../MyDocs/FT-install.sh" part. That's all. The phone will now reboot.

Just a last warning: I just tried it myself and something went wrong, I have red squares everywhere in the homescreen and the UI is messed up. Even the UI for entering the pin code at start up has glitches, so I am going to remove N9 Faster Transitions now.