All three options above are good, I highly recommend NordVPN or ExpressVPN, it's got Korea. Then use NaverTV or KakaoTV.
If you dont want to pay for VPNs, then Youtube. Or check out BigSoccer Korea, google it, find the match thread, and there's usually a few video links there.
I mostly use Relay which doesn't display subreddit designs, but I appreciate the effort anyway. :)
Big thanks for this post, but there are much simpler ways to watch K League live. As OP said, the 3 big Korean sites one can use, with a VPN, are Naver TV, Kakao TV, and Afreeca TV.
If you have an iOS or Android phone or tablet, or an Android TV, you can simply download any of those 3 as an app on your phone, tablet or TV.
If you want to use your computer, you can just search for those 3 sites, I don’t think you need to actually install any programs. It should be able to stream, just like Youtube or Twitch. But thanks OP for the post.
And for VPNs, NordVPN and ExpressVPN are the two best I’ve seen for Korea.