If you have or can find the link to them directly, you can certainly ask.
You did not say HOW you intend to use it. Will it be a blog post, an ebook you sell, or something other. Depending on how you use it, you could simply offer translation on your website, or copy paste the text from the ebook (if allowed) and translate it to another pdf or word doc, and pass it along with the original. In this scenario, you have not edited the original, only translated word for word.
Hope that helps.