How can i stop tracker on a folder on my memery card

I found this.

I edited /home/user/.config/tracker/tracker.cfg and appended to NoWatchDirectory the to be excluded directories.

anyone able 2 help me with step by step. i can get to step 5 but dont now where to edit it and what the directory of my memeory card is.

1) open x terminal and type 'sudo gainroot'
2) then type 'mc' midnight commander should open
3) go to the folder" /home/user/.config/tracker/" the "tracker.cfg" file should be there
4) finally just click on file and then edit.
5) ....