Buy the strip lights from amazon...$15. Cut the adapter off and use some heat shrink to connect to the existing wires. The strips should slide out and into the channel.
LED Strip Lights with Power Supply-16.4ft/5m Flexible Strip Light Kit, 300 LED Blue Lighting Strip Waterproof LED Tape Lights for DIY Home Kitchen Car Bar Party
https://www.amazon.com/dp/B07F9RQK5Z...dyvJEbQS9JJ3K*
There is no real way to fix the strands if they are waterproof without making them no longer water proof.
I installed the multi-color version under the trailer. It attracts fewer bugs and is not as bright because they are dimmable.