Bottom line is, back up your password well. I just wrote a guide going a little more into changing your owner key, and I have an older one about changing and using the posting key. See the bottom of this post for those links.
See also this post: https://steemit.com/bitcoin/@steempower/are-your-bitcoins-and-digital-asset-sufficiently-protected-backup-strategy-to-secure-seeds-databases-and-digital-files