The door handle on my gmc safari has a broken door handle

You more than likely will have to remove the interior panel on the door which will be fun and take some time. Once you have it removed you should be able to manually operate the linkage and get it opened. I would be ready to locate a new panel just in case you break the original one, but they usually have some give to them if you take it slow. You might try removing the speaker also if you have one in the back door. It might give you enough room to use a stiff wire with a hook bent in it to operate the linkage.