How to stop pumping?

Ive exclusively pumped for a little over 12 months now. Currently I pump in the morning when I wake up and at night. We do 1/2 breastmilk and 1/2 milk now that my son is 1. I would like to stop pumping but I don’t want to get engorged or have a plugged milk duct. Any tips on or directions for how to stop??