After it has finished flowering you can cut it all back hard, no higher than knee height. I would wait to move it either in autumn or spring. They have deep roots and are not too easy to dig up as I have discovered.

I doubt if its big you will be able to move it? mine had very big roots. Why not take a cutting and grow a new one where you want it?

I agree with the answers so far. It is very hard to get the root system out without it snapping because the roots go off at all angles. After cutting it back when it has finished flowering also try and take lots of cuttings in the hope that at least one or two will be successful. You may be able to dig it up and move it successfully but at the same time dont be surprised if it dies away after moving.