You take the plant you want to renew and cut it off at root level, or higher if you have a turkey neck on your plant.
Remove all buds and blooms and remove the lower leaves until you have a small crown of top leaves.
Fill a small pot with moistened seed-starting soil, make a hole the size of the stem with a pencil, insert the stem in the hole, and press the soil firmly around the stem. Mist the leaves and water in the stem.
Cover with a clear plastic bag and use a rubber band to hold the bag over the plant and keep in moisture. Place it under lights or near a warm east-facing window. When you can see blooms starting to open, it's time to take the bag off.
I restarted this plant on August 31st, and this is the plant out of the bag on October 1st.
I have been using this method to renew a plant that I got from my Grandma, who has been gone for more than 20 years.
I try to do this to my larger plants every fall so that they will bloom better through the winter.