You've changed podcast hosts or change the url, and you want to make sure RadioPublic is pointing to the right location. This is pretty simple but requires access to the old feed.
Setup a redirect
Contact your old podcast host and have them setup a "301 redirect" that points your old feed to your new feed.
Update your old feed
Add the itunes:new-feed-url tag to your old feed using your podcast host dashboard and point it to the new feed location. You'll want to add something like this to your old feed: <itunes:new-feed-url>http://www.myfeedurl.com/rss.xml</itunes:new-feed-url>
Once these changes are in place RadioPublic will detect the new location of the feed and update our systems.