Thanks for your question. I will try to help.
Basically, because more than 2 years has passed since your mother has passed away you cannot not carry out a legal variation to the Will.
This means that you must inherit the property, rather than backdating to the will to cut out it passing to you.
However, because there is no mortgage on the property it will be fairly straightforward for you to now transfer the property to your sons provided that you have the grant of probate. The land registry are good with simple registrations of transfers like this when they are submitted electronically by a solicitor under the Land Rgeistry’s Document Registration Service.
If you were to attempt to do this yourself then it would be time consuming and tricky because you would have to apply to register by post, which can take a lot longer any way but even more so because you may have to correct an error in the application which the land registry write to you about.
Additionally, the lease will probably require a notice of transfer to be served on the landlord and/or managing agent and the solicitor can check in this regard.
A solicitor would charge in the region of £350 + VAT to arrange the transfer, register it via document registration at land registry and to serve any required notice and this is really what you should do if you wish to avoid delay and hassle.
My goal is to provide you with a good service. If you feel you have received anything less, please reply back. Please remember to leave positive feedback using the stars at the top of the page.