Serpentine Belt

Would like to know how to change this belt and the routing diagram. The engine is a Honda V6

There is a tension pulley you have to turn one way or the other. There is usually a diagram for proper routing in the engine compartment…if not your going to need a Haynes or Chilton manual. This manual will also show you where the tension pulley is and which way to turn it

There should be a diagram under the hood - lift the hood and look up. There will be little decal right over the part. The diagram should be in the owner’s manual as well.
This is difficult replacement if you are not a mechanic; see if you can get a friend to help you. Getting the belt to fit over the final pulley can be maddening. You need to fit a socket wrench over the tensioner pulley nut and keep the tensioner pulley as far as it will go while you force the new belt onto the final pulley. I use a hollow pipe (about 1 foot long) that fits over the end of the socket wrench to provide leverage.