you should be able to unwrap that sticker and you'll see a clear tube underneath. You absolutely want to make sure all the glue from the sticker is off the tube before tanking it.
Ive never tried tanking one of these myself but the people that have commented on it have used an exacto blade to cut a notch in the tubing. They mention a triangle cut like the first cut a lumberjack makes with an axe.
Be careful with the blade, it will slide very easy on that plastic