Theoretically, there isn't. You have to reinitialize your REX to erase everything, then restore your data through a full sync.Technically, I've heard there are ways to expose this password through REX Tools.
It's hard to forget the password, however. If you set the password to show up when you wake up your REX, then Intellisync will always ask for it before allowing you to sync. If you protect a memo with a password, then it will ask you for it when it needs to update the memo (if it hasn't asked already.)
Note that password-protected memos are not protected in your PIM (Outlook). You could hide your password in a protected memo somewhere, then if you forget it you could look it up in your PIM.
