There is a tool set that you can use to remove the doors hinge pins and springs. You really need to have the spring compressor to remove the spring without loosing some fingers or damaging the doors.The factory pins have spots pressed into them to keep them from falling out. You will need to grind those spots away in order to remove the pins. Pay attention to which way the pins came out and install them the same way. Check the holes where the bushings are and make sure that the holes are not egg shaped. If thats the case putting bushings and pins in won't do any good. The pins will break the new bushings. An extra hand with the door will be a big help also. 
