Yes, you will want to remove the door, track, and the trim around the opening. You will have what is called a rough opening, that you will install the new door into. As mentioned before you can buy a regular door with the frame at a retailer. Take a look at the opening and figure out which way you want the door to open (to the right or left).
You will also want to pick up some shims (used to level out the door in the opening). Personally I like to screw in the door Jamb (frame) to the opening this allows me to adjust it without hammering and prying it back out. The pre-hung door that you purchase should be slightly smaller than the rough opening you have (after you remove the current door and frame), a 1/2 inch is barely enough an inch is normal but 2 inches may be a bit too much.
So once you have the door home, leave the door in the jamb, and leave the little plastic thing holding the door in the jamb (through the door knob hole). Start by leveling the side with the hinges, using the shims where you screw the jamb to the opening. Once you have the hinge side set, go to the other side, trying to keep the gap around the door uniform.
It may sound daunting, but really it is fairly simple, using screws allows you to try, test and adjust until you are happy.
Then once you have the door in you can replace the trim around the door, you may need or want new trim. It can break easily when you remove it and the new door and old door may be slightly different size.
Ex Realtor, house flipper, remodelor and now building a vintage truck, making friends and fixing my house.
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