Hello Frank:
I am too old and too fat to be climbing onto a billboard to swap out vinyls…What did you pay to swap out billboard signs?
You’re right, you have no business up on a billboard unless you know what you’re doing, can adhere to OSHA and have insurance.
In most markets, it will cost about $500 to drop an existing vinyl and hang a new one. But all that matters is your market. Get at least three bids and see what the lowest one is.