Fee to register a Deed of Variation

I have a signed Deed of Variation in respect or enforcement of the rentcharge applicable to my property. This variation has been requested by my purchasers solicitor/mortgage lender.

Please advise what form required to register a copy of the DoV and the applicablle fee 

Thanks

Natchamin - a deed of variation of a rentcharge can often be noted on the register in most cases. Form AN1 plus £40 fee 
Agreed notice: registration (AN1) - GOV.UK
Do seek advice from your conveyancer
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.

Many thanks for this information