My right rear door will unlock but not open.

Hello, The linkage is likely disconnected from the latch, or the latch is defective. Replacement parts are typically cheap, and the diagnostics will involve part of the labor needed to replace the damaged component. You are probably not going to be disappointed by the cost of repair, but you can do it much more economically by removing the door panel, looking for a broken part, and having Nissan order it for you.