Do NOT use machine translation for such an important thing. Legal documents meant to be used for official purposes should be translated by specialized legal translators. And you should check out to see what sort of certification your document needs, since sometimes only a registered translator can provide the stamps required by the court. Since legal is a local thing, you may have to stay with local resources (ask court officials), but you can also check out bigger translation agencies, even from abroad. You'll find a lot of stuff on the web, like this Translation Firms directory. Most big companies have free quote tools to see what sort of money you'll need to spend.