The exact instructions on fixing your pop-up camper lift system will depend on the model, make, and year. Older models have a crank and pulley system while the newer ones have a cable and pulley system. You might want to check with your local RV dealership to help determine which type of pop-up camper you have. Many times the fix is as simple as slipping a cable back into place.
Fixing a pop-up camper can be as simple as a slipping a cable back on, or as complicated as having to install a new cable system. Some older models use a crank and pulley system. It would be best to check with your local RV dealership for more detailed instructions for the specific model you have.