How do I enable password sync post-installation?

I personally don't think storing passwords inside one's browser is a very good idea; neither is it a good idea to store them off your computer in a public domain no matter how secure it may be. Using an encrypted password manager like KeyWallet is a much better idea. You can find a whole list of free Passwords Managers here: http://www.techsupportalert.com/best-.... Backing up the encrypted file that stores your password is a good idea, but the only place off your computer that should be stored is whatever media you use to store your backups; floppy, tape, cd/dvd r-rw, or whatever. But then that's my opinion based on years of security experience.

But with that said; you don't mention which browser your using. I only have XMarks installed on Firefox as and extension add-on.

In Firefox you need to access Add-ons (in the Tools menu) then access Extensions, the click on XMarks, and then click on Options. No matter which browser you're using find XMarks options and open it up.

When the options dialog opens up click on the "Sync" tab. The top option is "Synchronization Types"; below that you will see the input check box for "Passwords" Check that box and you should be in business. Let us know how that works for you.

I don't think it's a very secure thing to do with your passwords, but that's how to do it.