Property Transactions that are not 'Accumulated Rent' can be transferred to either another Property, or to the Buffer Account, if they are created in error. (Property Transactions that are accumulated rent transactions cannot be transferred as they are automated transactions).
Go to the Property screen, and click Property Transactions. To transfer a non-rent Property transaction, double click on the transaction you want to transfer. Tick the box.
If you are transferring the transaction to another Property: select the Property in the box so it is highlighted, and then click the button.
Clicking Yes will transfer the transaction to the Buffer Account.