Disposing off the property

hello,

there is a property which is registerd on the name of both husband and wife.the wife is mentally ill not physically fit.the husband wants to dispose off the entire property.they hav kids who r major and they dont hav any problem with the disposition of the property..

1.my question is how can the husband sell the property ? 

2. wife being mentally ill cannot give the consent..in such case what is the procedure...

plzzzzzz help

thx