ARMA self-service library offers guidance to leaseholders. We would recommend that you view the documents available to see if they can assist.
If they do not, or you require further information then please contact the Leasehold Advisory Service at email@example.com. They are a government funded body who are able to assist you and they provide free information, initial advice and guidance to members of the public about residential leasehold. They are independent and impartial and all of their advisers are legally qualified.