It would depend on your reasons for wanting to transfer.
Firstly it would depend on whether the property is Registered or not, i.e. do you have a bundle of deeds or a title document.
Unregistered - this will cost more to do as you will have to use the services of a conveyancer / solicitor. They can do the registration and transfer to sole name in one application, and last time I checked the Registration fee will depend on the value of the property. The solicitor will have to submit all title documents which will then be electronically stored and a Title Document sent to you - all in all you should expect a fee of £350 inc VAT and registration fee.
Registered - You should be able to do this yourself without the use of a solicitor. You can download form TR1 by searching on Google. You will have to insert both your names under the Transferor section, and then just your wife's name under the Transferee. This will need to be sent to your local Land Registry office with a fee of £40.
Hope this helps