My b2evolution Version: 1.10.x

Just getting b2evo to work after a new install. I'm completely new to this as well as anything related to the back end of the web so please bare with me.

I'm trying to get one install to run on 2 domains. The primary domain (domain.com) is working fine but I want to add a blog and have the absolute url to be another domain (domain1.com/blog). I am getting confusing instructions both in the Docs as well as from past forum posts. Do I have to modify the stub file? Do I have to modify the .htaccess file?

Being a super novice, can someone spell this out as simply as possible? To give you an example of how novice I am, I am not sure of how to modify the .htaccess file (or even access it).

Thanks in advance.