The other way to transfer a plot is to sell/pass the rent rights to a specific account. In this case, you send a proposal to the selected account. You have to set the price if you want to sell the plot. You can also enter a price of “zero” if you want to pass this plot to the chosen person for free. To finalize this transfer, the account has to accept your proposal.
You will be able to look over any proposals that anyone has sent you in the Land Registry window. You will have the option to accept or delete them. In either case, pay attention to the contents on your plot. All the property, including anything in the storage, will be sold the moment you confirm your action of selling/passing the plot at the end of the auction. So move items from storage before selling if you don't want to loose them.
You need to click the "Pass on" button, then write the account name of the new owner and the price of your deal. The new owner must confirm your deal in his account.