Determine who currently owns the digital rights to the book you wish to purchase. The best way to determine this is to contact the author. The author will be able to inform you if the digital rights you seek to purchase are still owned by the author or if the author has already sold to rights to someone else, such as their publisher. If the author has already sold the digital rights to the book, you will need to contact the current owner with a request to purchase.
Create a contract to purchase the digital rights. If the current owner (author, publisher, or other) agrees to sell the digital rights to the book, you should create a contract including the details of the transfer of the rights. The seller of the rights may require you, the buyer, to make a payment in exchange for the sale of the rights. The seller might request payment of a lump sum at the time of purchase or a percentage of future income earned from the electronic format of the book--known as royalties, or a combination of a lump sum and royalties. This information should be included in the contract, which is a legally binding agreement.
Transfer of ownership is complete once both parties agree, sign, and any initial payments are made as outlined in the contract created for purchase of the digital rights.