Secondary latch on spare won't release

Have tried everything. Soaked with WD40, hit with a hammer, used the jack as instructed in the manual and still can't get the secondary latch to let go. The cable is working as it comes down to the ground but the tire lowers only a few inches and stops.

any other suggestions?

If you have not solved this problem i had a similar problem with an 04 suburban. lower the tire as far as it goes and if u use a screw driver u can see up thru the tire and if your lucky you can trip the latch and get the tire down. we had to reach over the top of the tire and use a hand to trip the latch without dropping the tire on someones head and then lubed it with white lithium grease, use transmission fluid at first, it penetrates really good! try these out and lots of luck!!!

i have the same issue, i found a video on youtube that showed how to lower it (if its rusted) but i tried and could not do it
i think what im going to try and do is cut the lip that stops the latch and there by disable the safety latch