You can Upload them to Youtube and get them to generate subtitles for you, if you cannot find the lyrics on the web.(MUCH easier!)
These subtitles can then be downloaded (advanced IT know-how necessary for FOSS installations).
Using online translators like https://www.deepl.com/translator you can understand the text.
So, hopefully you find the lyrics on the web. Mostly, they are there.
Good luck!
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