stuck tailgate on my 77 ..

[1966bmx]

hey everyone ,
i gotta think i am not the first this has happened to . my tailgate is stuck closed on my 77 cheyenne . the handle has no tension in it it just kinda flops up and down . so it is not operating the rods anymore obviously . seeing that there is no access panel on these tailgates . i do not know how to go about getting it open and fixing the problem . has anyone else here heard of this or had it happen to them ? how did you fix it / get it open ? i tried the search function but did not find anything . unless i am searching wrong . so sorry in advance if it has been posted before . thanks ,
donnie