Playing jazz lines isn't hard. In fact it's easy. What's hard is attaining fluency but, like anything else, it comes.

So here's how we start. Take a C major scale starting on the 5th string. Play it up and down till you know where the notes are and also what they are. Start with your 2nd finger on the C.

By the way, actually click and play this diagram:

(Set the Sound to Elec Jazz)