By all means talk to your local District Land Registry office - the link is
here - once you have recognised your Administrative Area click on Local Office to see full details. Deeds have been done away with for years now, it is the name on the Registration at the Land Registry that you seek to change.
However, if your mortgage company insists that it is done through a solicitor you will have to accept this, I'm afraid. It is to ensure that nobody takes unfair advantage of them. Cost around �200.