Campanula persicifolia division

I have several Fairy Bells and one of the clumps has not flowered this year as it needs some division. I would like to divide now rather than wait till Autumn as I am working on a rockery and a piece of this would be ideal in a central position. Have heard this plant likes well drained soil so will add grit. Not had problems with slugs and snails with campanula but will be looking out for damage nevertheless. Hoping the division takes and may have flowers next year.