How to access the intake manifold?

I came across a post to solve the P0420 code using a spray can, and I would like to give that a try. However, the person who posted that article, doe snot provide details about how they did "spray[ing] short bursts of fluid in through the intake manifold" - I am not good at mechanics. I used to clean an old carburettor in an old Dodge Colt many years ago. I could spray directly into v carburettor - But with the Prius 2007 I have now, I don't know where to "spray the short bursts".

If someone could provide directions on how to access the "intake manifold" I would greatly appreciate.

Thanks. Blessing to everybody here.

 

Thank you, Tombukt2

So, According to what I've found the code I am trying to get rid off, is more because of the "gunk" covering the sensors that trigger the code. And the post I've found successfully cleared the "check engine" light after using the chemicals. Since this is a new account in the forum, It's not allowing me to send the link. I'll try it once that restriction is removed.

Thanks, mr_guy_mann

 

Will try it according to the post I found instructions. I'll update on this matter here.