Summarize the following:
There should be very little soil left. When it does need to be repotted, move it into a container that is no more than 1 inch larger than the old one. Put 1 inch of potting soil into the new container, gently remove the Hoya from its old container and set it in the new one. Fill in around the roots with potting soil and water it generously to settle the soil and give it a good drink. It will bloom again on that same stem. The faded flowers can be snipped off with sharp scissors just below the flower.
Do not repot the Hoya until the container is full of roots. Repot your plant with peat-based potting soil. Leave the flower stem on the Hoya after the blooms fade.