The gears in my dakota move over park is reverse, reverse is nutral, and nutral is now drive. Does anyone know how serious is this problem do I have to replace my transmission.

Sounds like your shift indicator has moved. Put the transmission in park and see if you can adjust the linkage to show park. Then do it for drive.

Check the transmission linkage under the vehicle it has obviously moved.

check the transmission linkage under the vehicle it has obviously moved.

Not necessarily. Often it is only a matter of adjusting the gear indicator.