Doors will not unlock
 

The driver and passenger doors on my 2001 Elantra will not unlock. I changed the battery in the fob and that was not the problem. When I click the unlock or lock button, I do not hear anything moving. When I tried to unlock the doors manually, the key will not turn in the doors.
The trunk will open but I have no way of getting into the car. Since the transmission is shot and will cost me $2,400 to fix, the car is going to the junk yard, I just need to get into it to get my things out and I do not want to have to spend money to fix this problem. Trying to avoid having to break a window to get in because the will lower what the junk yard is paying me also.
Any advice is appreciate.
Thank you.

Push the rear seat backs down from inside the trunk and crawl through.

The seats will not go down because the release lever is in the back seat which I cannot get to???

Have you tried all the doors? Click the fob twice to unlock all the doors and then try to open a rear door? Are you sure the battery in the car is good to operate the keyless entry?

As I stated in my original post I put a new battery in the fob so I know it is working. I have 2 fob & replaced battery in both. Yes I tried opening all 4 of the doors.

And as I stated in my post above:
If the battery in the car is dead, it can't receive the signal from the fob and it can't operate the electric actuators.