It should be easy to open, but if it isn't, you should be able to adjust it so it is.  

Ours used to be quite easy to open, but when we had the dealer do some work on it, they "adjusted" in such a way that it takes some effort to open it now.  I called the factory, and they said there was a counter weight that could be adjusted to make opening it easer again . We will be taking it back to the dealer so they can "adjust" it back.