I have attached the question as jpg to this post. Typing these were too time consuming and I uploaded the relevant sections as image files, thanks for your understanding.
mu_0*epsilon_0*Poynting Vector = Momentum density
Position vector X Momentum density = Angular momentum density
The Attempt at a Solution
These too are attached in png format.
I have found out that angular momentum density has two components, one in the z direction and one in the x direction. According to the books solution the x component integrates to zero but I was unable to verify this and I am highly skeptical about this topic. Any help would be appreciated. I have attached the relevant information to this post.