The stalks and leaves will flop to the ground and disappear, the goodness being drawn back into the roots, so just leave it to do its thing, and give the plants a mulch of FYM on top of the shrivelled stalks. New shoots will pop up in about Feb.
If you treat it well and are not greedy, rhubarb can grow huge. One year we had two birds nesting in neighbouring rhubarb plants - one a blackbird, the other a hedge sparrow! The chicks fledged the day of a huge storm which totally flattened all the plants, but at least the birds were ok.