Thanks so much for wanting to help us translate our content.
To translate our content, you can use the YouTube's subtitle editor. You can access the subtitle editor by following this link or by going to any video and clicking on the "More' button. Then click on "Add translations."
If "Add translations" does not appear, click on "Transcripts," then click on "English", then click on "Add subtitles / CC."
You'll then be brought into the translating tool. Once you've finished working on the subtitles, they'll be sent to our team for review. There may be a couple week delay between the day you submit and when it becomes live on the site.
Thanks again for wanting to help us out!