You cannot force the mortgage lender to remove you from the mortgage. Therefore the only way you can be certain of being removed from the property is by selling the property.
For what it is worth a deed of trust whereby your wife is entitled to 70% of the property and you are entitled to 30% does not necessarily carry much weight in divorce. You should not assume that is your entitlement just because your wife says it is. Divorce law is not so easily circumvented.