The XAUTH password is generally your company login. It is NOT your equinux ID. Your XAUTH is stored on your VPN gateway or on some remote server your VPN gateway asks for authentication (LDAP server, RADIUS server, Active Directory Server, etc.). If you do not know it, or need to reset it, ask your System Admin for help on this.
VPN Tracker or equinux have nothing to do with this password. Your VPN gateway just tells VPN Tracker "Ask the user for a username and a password and tell me what the user has entered" and that is what VPN Tracker does and in respond to the information the gateway replies "Sorry, but that is not valid username-password-combination, I can't let you in, bye".
In VPN Tracker you can just click on the blue label next to the XAUTH setting and the XAUTH dialog will appear; just overwrite the existing values with new values.
See page 16 in our manual