You could try Google Translate - if you can get the original text into it, you can usually get just enough out of it to follow the proof. If your pdf isn't the kind where you can cut and paste, you might have to type it in manually.

If you're just looking for a proof of L'Hopital's Theorem, you can probably find it in a calculus book or a book on analysis. It's about a page long in Rudin.

- Hollywood