Removing a historical rentcharge from my title dead that is over 60 years old

My property has had a rentcharge of £1 listed on the title deed since 1915. We have no contact with the current rentcharge owner and neither did the people who lived here before us. My understanding is that under the Rentcharges Act 1977 if this rentcharge is more than 60 years old then it is no longer valid and I can get it removed. Is this correct and how do I go about doing this?

Sarah - if it's a noted rentcharge then you can apply to cancel it using form CN1 together with supporting evidence as appropriate - Notice: cancellation (CN1) - GOV.UK 
The 1977 Rentcharges Act provides for the extinguishment of existing rentcharges after a period of 60 years, normally beginning on 22 August 1977
A fixed fee of £40 is payable by cheque/postal order to HM Land Registry
Postal only application - HM Land Registry address for applications - 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.