Here is a small howto on how to submit a patch to Agda2:
You will need darcs installed on your machine, and a copy of the darcs repository (see instructions at Download).
A good practice is to make sure that you have the latest revision of the repository:
darcs pull
Then copy your files to the place where you want them in the repository, for instance:
cd Agda2/examples/AIM6/ mkdir NiceExample cp ~/mystuff/NiceExample/* NiceExample/
The next step is to add the files to your local darcs repository:
darcs add NiceExample NiceExample/*.agda
And record changes as a darcs patch:
darcs record -m "This is a nice example"
darcs should ask you some questions, e.g. your email address and which changes you want to actually record.
The last step is to send the patch to Ulf so that he can add it to the global repository. If you have a working sendmail installed on your machine, you can just use darcs send. Otherwise, you can generate a patch file with:
darcs send -o niceexample.patch
And you then just have to send niceexample.patch to ulfn@cs.chalmers.se.