Hi,
sorry for the late reply. The blog post lacks screenshots on purpose, for reasons already pointed out by @anon33261557. Personally, it is hard to find a balance between make using IPFire as easy as possible in order to be helpful to as many people as possible, but do not oversimplify it at the same time.
This being said: If any questions appear while setting up specific firewall rules, I (or somebody else, whoever responds first 
) will be happy to answer them.
Thanks, and best regards,
Peter Müller