and say you are willing to help with subtitling.
Find a drama which hasn't been aired yet (Coming soon), go to its main page and see if there is a Spanish moderator on the cover page. For instance, here https://www.viki.com/tv/35620c-hwayugi you will find this part on the cover page.
and send her a private message saying that you want to be part of the team. In most cover pages the names are also links, so it's enough to click on them. If they are not, then use this URL:https://www.viki.com/users/USERNAMESubstitute USERAME with the real username of the person. For instance, if the moderator is tess6, you will write the url like this:https://www.viki.com/users/tess6
When, either from the link or from the URL you typed, you are taken to her profile page, on the top left block, under the username, you will see a little envelope. Click on this and you will be able to send her a message. Or you can use this url: https://www.viki.com/messages/new?username=USERNAME(again, substitute USERNAME with the real username of the person.
For Hwayugi, which is on air, obviously the team has been formed more than a month ago, so don't bother writing to the mods. They already have thirty four people for Spanish! You should look for shows not aired yet.
como le hago para subtitular?