The situation is not unusual and the government have put together these guidelines for exactly the circumstances.
and I can do no better than send you the link which explains the process in detail.
Unless you have experience of registering property, it’s probably a job better entrusted to a solicitor because the Land Registry have unnatural and inherent distrust of people trying to register property themselves.
Can I clarify anything for you?
Please don’t forget to rate the service positive. It’s an important part of the process by which experts get paid.