Door hinge question ?

Have a 61 econoline question . On my door hinges . The guy that has been working on my van was trying to replace the hinges . I think you on one of them it is going to be replaced because he has messed it up . I have some extra doors with hinges . How do you get the hinge out of the door ? You can’t unbolt it and how would you replace it with bolts ? Thanks for the advice.