I just went out and looked at mine. Just like Craig said, the small lever controls the release of the latch and the long one serves to open the hatch and also provides leverage to lock the top down. I don't know that there is a good backup plan. I don't see how you can get to cables with the top on.
The only thing I can suggest is with eveything loose, give the back of the top a shove toward the driver's side - that is away from the notch in the latch.
If you send me an email, I will send you the owners' manual which has instructions and a picture.
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe