If you are referring to the safety catch for the lift system it is accessible from beneath the trailer and almost directly below where the wire loop is next to the raise/lower switch. You can spray some silicon lube into tube that the cable goes to the catch to slicken that up, then you can crawl underneath and clean and lube the catch which is the long flat steel strip the parallels the hydraulic lift cylinder. There can be crud built up on the end where the release cable connects to it. Give that a cleaning and give the area a spray of lithium grease or similar.
While you are under there clean an lube the guide rod that keeps the hydraulic cylinder in line, Thats very important!