Getting a visitor visa in Seoul, need info ASAP

First off, sorry to post this here, I just spent a lot time trying to find this info and couldn’t find it here.

Hoping to get a visitor’s visa this weekend in Korea, (I’m already in Taiwan). Can anyone who has already done this or knows about tell me how long it took and how difficult it was. I’m hoping to use the papers from the Chinese school I’ve been at for a month already, or do I need ‘new’ papers???
Thanks for any help.