Yes, you can always replace the doors yourself and simply have a door retailer deliver your new doors to your home. It all depends on how handy and experienced your carpenter skills are. If your new doors do not need to be reframed, it is plausible that even someone that is only a little experienced may be able to remove the old doors and install the new doors. Without reframing, you should only need to pull the door off, remove the hinges, then measure and screw the new hinges into place. Then bolt the door to the hinges on the frame. However, if you are unsure in any way, it is better to hire a professional to prevent costly mistakes that end up costing you more in the long run.