First of all Rainbow Prince is a true labor of love, you really need it to produce something so cringe, awkward and over the top.

Rainbow Prince is the "Disney" channel mid-2000 musical that was accidentally blended with BL. So we have a cheesy plot with more plot holes than cheese, Disney logic (or her lack) various quality songs and dance numbers.

But let's move to instruction, first you need to go through 3 phrases:
1) It's bad - are they serious?
2) Huh? It getting even worse?
3) It's so bad is started to become funny.

To archive 3 phrase you need to turn off your brain, a bottle of Prosecco or better 2 - depending of your % tolerance and drink every time you think it's bad while singing along to RP song (The effect become better if you try to mimic the original choreography).
Doing it with a friend double effect!
Personally after 2 episodes I was crying with laughter and having the time of my life.