Okay! Gotlots ofgood info on that post and we have some pretty amazing info posted online by Winnebago. At least we can get an idea or two of how things work and where.
Parts catalog here is interactive and we can choose which parts to look at:
https://catalog3d.winnebagoind.com/2012/177535.htm
A bit of time to learn how to "drive" it but great for looking close at things without having to tear things apart!
Sorting down to your RV, then looking for the right rear slide we can look at the slideout and finally get to the latch!
You may have quicker luck if you already know where to look but I found this set of pictures.
First is view from inside looking toward the outside and from above. Maybe to helplocate general area as it looks above a window? Maybe center of slide?
Second is fromside to show hook, controlled by arm of mechanism?
Third from below looking out again.
Four is detail of mounting screw holes and looks like a small motor driving a shaft through a gearbox that then moves the hook above?
So the big question for you is what to do now!!
Does a spray of lube from above seem possible as an easier thing?
Do you have to remove some of the interior cover to get to the motor, etc to free some sticking parts? I assume no access panel!
Sorry, I'm no good at the blood, sweat, and tears part!
Hope it gives you some good ideas to work on from here.
EDIT:
Sorry pics did not post in correct order as I numbered above. I think you can get the ideas?