You can edit your Podcast's name at any time on your Podcast management page under the "Settings" tab. You must consider the following, however, before pushing the changes live:
Changing the podcast name will also change the 'slug' used in the URL of the XML feed. This will make the previous URL unreachable, causing your podcast to fail on any apps still syndicating it.
As such, changing the podcast name will require you to update your syndicated listings on all Podcast apps and platforms. Be sure you are prepared to do this before making the decision to change your podcast's name.