Do you mean a herbaceous one or the shrubby Fruticosa?
Assuming its the shrub wait until all the leaves have fallen and the shrub is dormant. Dig the hole that is to receive it & then dig it up carefully, damaging as little of the roots as possible and transfer to the new hole. Backfill the hole and tread round gently it to firm the soil. If the shrub has been in the ground for a number of years you'll have to take extra care not to damage the roots any more than you can help. You might shorten the branches somewhat too. If its an old and really well established shrub it might not survive the move.

If you mean the herbaceous one just dig it up and move it in the autumn.