95 Chevy Tailgate linkage

[vine]

Hello from Canada. I am enjoying my silverado a whole bunch. I think its the best truck I've ever had. I bought it in 2000 and I haven't spent anything on it other than regular maintenance stuff. I love the 350 in it! I have a question about getting into the tailgate linkage. The locking pins on the sides are starting to not close after opening. I can't see any access panel so I am wondering how to get to the linkage to clean it and lube. Hopefully this will solve the problem. Thank you in advance for your help and suggestions.