If your current podcast hosting does not allow you to redirect your podcast feed to RSS.com you have to manually change the podcast feed URL in Podcasts Manager.
1. Login to https://podcastsmanager.google.com
2. Click on "Settings."
3. Click on "Feeds" on the show homepage in Podcasts Manager.
4. Click on "Change served feed." You will be prompted to select which new feed to serve:
- If the feed is in your show's feed history, choose the feed from the list, and the change should happen in a day or two without any additional verification.
- If the feed is not in your feed history, enter the feed URL and you'll be prompted to verify ownership of the feed, as with any new feed. You will receive a verification code by email, and must provide the code in the verification flow to complete the process of changing the feed.
5. Visit your show in Podcasts Manager to see if Google has made the change.
6. Update your podcast hosting service and your RSS feed.