Selling my share of Land

Person X owns land with 3 other people (Persons A, B C) as tenants in common. Persons B, C & X are looking to sell/gift their share and person A is wanting to keep their 25%. Please advise which forms are required to be populated to update the land registry to the 3 new owners?  

J Wallis - see our online guidance on how to transfer the legal ownership - Registering land or property with HM Land Registry: Change the registered owner name - GOV.UK
Land registration is complex, designed to protect legal and financial interests in property. There can be significant consequences for any error. Please consider seeking legal representation. Before making an application without legal representation, It is important to consider the benefits of using a conveyancer.