Many thanks Ancelad/Coderus, you are lifesavers

I did it like this:

1. Install Ancelad's N9 Repomirror manually.
2. In config, go to Applications -> Manage Applicationss -> Updates and touch on the update icon, wait until it finishes
3. Enable Developer Mode.
4. Execute devel-su and install nano
4. Go to /etc/apt/sources.list.d, nano aegis.ssu-keyring-00X.list and comment all lines, save it.
5 profit.

Step 4 is mainly to avoid some errors Warehouse gives when updating repositories.

Greets

PD: After installing Developer Mode you may need to comment lines on sdk.list too, or will get apt-get update erros again.