Removing deceased husband from title deed

Posting on behalf of my mother. My husband passed away 2 years ago and I'm aware his name is still on the title deeds. I'm currently getting my affairs in order and would like some guidance as to the procedure to follow to remove his name and is there a cost involved. I am unable to locate the title deeds number.

Kelvin - see form DJP. There is no fee. https://www.gov.uk/government/publications/deceased-joint-proprietor-djp

Search online to confirm the register and title number if the property is registered https://www.gov.uk/search-property-information-land-registry