There is a video tutorial in that wiird website (even it shows/uses prior version of the tools, but the steps are still the same I think):

http://wiird.l0nk.org/forum/index.php/topic,2260.0.html

You activate the grass restore code when talking to Rover (he always asks your name before you start the game).

I think the grass can't be trampled code only works when it is activated while playing with geckoos.

Hope this helps.