I just did a project where I changed out 15 hollow core, 2 hinge doors to solid slabs that needed a center hinge added. In your case it's easier because your doors and jambs are mortised for hinges. Just take off the door, remove the hinges and replace with new hinges. Just get hinges with the same radius unless they're square and you won't have any issues with changing them out.
The only issue you may have is, if one or more of the existing hinges is shimmed because the mortise was cut too deep, or some other adjustment.
Do one door out of the way. You'll see it's pretty easy.
If you have a lot of hinges to buy, I found they were cheaper online rather than HD or L's.
You might also consider using a longer screw for the new hinges to keep them tight, or just snap off a tooth pick into the old screw hole before the new screw.