You need to drill a hole at the top of each lens, at the widest point with the dremel. The hole should be big enough to pass the cables through.
Get a sharp Stanley blade and very carefully put the blade between the joint where the lens meets the backing plastic, slowly work the blade around the lens joint until the 2 halves split apart, this will take some time. You will have to lever the blade in the slot you cut to make the two halves split.
Once apart, lay the led strip on the thin upright and secure with strong glue, superglue won't work!
Use a glue gun and place a dob of glue at the bottom of the LEDs.
Pass wires through the hole you made, and reassemble, don't use superglue it will coat the inside of the lens with a white coating.
Use a dob of clear silicone sealant to make good the hole where the wires come out.
Wire into the side light cables job done.
Will take you about 4 hours to complete. Note, the dremel tool will cause the plastic lens to go soft, stop, allow to cool and carry on drilling, repeat until you get through.
We used a pink grinding stone to make the hole, don't use a drill, this will shatter the plastic as it breaks through. Patients is the key.