The movie was spectacularly bad, but had two good parts to it. Here is a guide to watching the movie if you have it on DVR or some other linear medium that does not allow scene hopping, but does allow fast forward.
Start the movie and immediately hit fast forward. If you have 3 fast speeds, choose speed 3. If you allows yourself to hear the beginning of the movie, you can't say I didn't warn you. It starts out rather vile, then generally oscillates between being nasty and banal.
When you see the men in white sheets, get ready to hit the play button. Once Harold and Kumar start flagging down the little red/orange car, hit play. The scene is a bit ribald, but only thanks to some language. Neil Patrick Harris is great as "himself" in both Harold and Kumar movies. If you are clever with searching YouTube, you can find the two clips that combined make up NPH's time in the movie. One has "Takes Shrooms" in the title and the other has "Brands a Ho."
Once NPH exits the brothel and is done trying to get in the car (you will know when his attempt is done), go back to fast forward.
When you see Harold and Kumar falling from a rather high place, get ready to hit the play button. When the groom walks back up the aisle and past the bride, hit play. Here is the good part and here is the text of the poem: The Square Root of Three.
That's it. You have seen the best parts of the movie. Actually, you could probably same some effort if all you do is watch the clips at YouTube, but suit yourself.