This will wipe your device of all data and personal information after the 10th wrong attempt.
FIRST, do total backup with the Desktop Manager on your computer. Then use up the attempts to enter a password for the Key Store until you hit the 10 and WIPE point.
Then go to Options, Security, Key Store. Enter new password and verify by typing it again when asked. If you want to have this password the same as the master password, click the button to "Synchronize Key Store Password to Device Password." Note that the Device Password must be enabled to do this.