I understand your concern, not being able to open the freezer door. This is a very unusual problem. There is nothing that should be keeping the door, from opening. It's possible for the door to be in a bind and be a little difficult to pull but it should still open. To determine what could be taking place, the freezer door will need to be removed. First disconnect power to the unit. To remove the door, take the top hinge cover off and disconnect the wire harness connection. There will be a water fitting under the door for the water line inside the door. I'm attaching a picture with instructions for this type of fitting. Take the water line loose at the fitting (some water will come out) and now take the top hinge loose. It should have 3 screws holding it in place. The door can now be lifted up, off of the bottom hinge and removed. With the door off, you may be able to determine, what is causing this problem. I hope this will help you. If you would like more assistance, any additional details will be helpful and I will be glad to assist you further.
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services