Jorge (and others),
Please take a look at the translation server (http://translate.dotlrn.collaboraid.net/). It's THE place to do all the translation work, if at all possible. Please ask Peter (peter at collaboraid dot biz) to give you translator rights after you've logged in.
If there's no way you can use the translator server, you should be able to do the translation even on your own OpenACS instance. You can find the getting started guide on the front page of the tr. server. It applies even to your own box. Please remember that if there's more than one people taking care of one language (like in your case) it's much easier to coordinate your work if you all work on the translation server.
NOTE: you cannot do the translation on openacs 4.6 and dotlrn 1.0 branches or tarballs. Both have to be checked out from CVS head. There's no way around it.
