Not being the domain expert

Being the non coder of my team, I'm the domain expert. Well, that seems to be correct: I'm the product owner proxy, requirements analyst and manual tester, all in one. But now, when we're turning to working more with issues concerning system installation, I'm not the domain expert. And I need to be as good as the guys and realize that and take this as seriously as we do the "ordinary" domain. I can't call it user domain, because users work with the system installation.

I need to create a mental model of how the system installation works and get cracking learning all the domain terms of system installation. Tables are turned, so to speak.