Removing a name from a tenancy agreement

Tenancy Types and Management

Good afternoon

I have a married couple whose both names are on a tenancy agreement which does not expire until 5/7/14. The couple have now separated and the husband has vacated, the wife will continue to stay on at the property. She has asked that I remove her husband from the tenancy agreement, is this ok to do this and draw up a new tenancy agreement for the remaining months up to 5/7/14. Do I need written confirmation from the husband confirming removal of his name from the tenancy agreement?