How can I translate YouTube subtitles into another language?

I want to translate the subtitles (captions) of a YouTube video into another language. Some videos already have auto-generated subtitles, while others have manually created captions.

What is the easiest and most accurate way to translate YouTube subtitles? Can this be done directly on YouTube, or do I need to download the subtitle file (SRT) and use a translation tool such as DeepL, Google Translate, or another AI-powered service?

I'm looking for methods that preserve subtitle timing and formatting while providing good translation quality.