There is no easy way.
I use Google translate text. I was using it this week to support someone in Italy. I have an Italian translator but she wasn't required most of the time.
Google translate text will work for most things but you should still get a German to English translator ( a real person ) to sanity check the results. German and English have idioms or sequences of words that don't translate well.
"What kind of a car is that" translates to "Was für ein Auto ist das?" which if you translate word for word means "What for a car is that?". That blew my away in German class and I will never forget because I missed that on a test. That is when I first became aware of idioms. There is know easy way to translate the idioms and slang. You just need to know them.
BTW, Google translate text got that right.