Much as I hate paying 'professionals' for tasks which can be done by any reasonably-intelligent individual, I'd still strongly recommend using a solicitor here.
To do it yourself you'd first have to identify the correct form from among this lot:
https://www.gov.uk/government/collections/hm-land-registry-forms
(TP1, possibly?)
You'd then need to fill it in correctly, which includes 'executing the transfer as a deed' in accordance with the provisions of Schedule 9 to the Land Registration Rules 2003. The possibility of making an error in doing so would seem to be too high to take a chance on getting it right.