Request - translate one page into Spanish

Dear team,

After checking
https://www.w3.org/International/i18n-drafts/pages/translation.html, I
would like to translate the following page into Spanish:
https://www.w3.org/International/questions/qa-site-conneg

I am a localization professional working for a large language services
provider, but I would perform this task individually and in my free time
(my company is not related to this request).

I would need the zipped set of files. Do you use or recommend any
translation editor/CAT tool?

Very happy to collaborate on this project, if you agree. Please let me know
if you need any other detail from me.

Thank you very much in advance, with kind regards.
-- 
Enrique Díez Fernández