There are two situations. One is when you have your own lyrics:

If the lyrics are wrong, click here to search, and then click "Find the lyrics file locally" to upload your own lyrics.

The other is when there are no lyrics:

If there are words "Welcome to upload lyrics", electrocute. Then click "Browse" and upload your own lyrics.

Only in these two cases, you need to have your own lyrics to upload successfully, and you can also upload the lyrics of other songs to different songs.

ok, that's all. You have a try.