Estimation MEP - Creating and Taking Off Mechanical Assemblies

This video shows how to create, save and takeoff custom Mechanical assemblies in Estimation MEP estimating software.

[@ChristopherJanke]

At the time of this comment, there is no "Assembly Library" to select. Instead, I have a "Work Breakdown" option. Additionally, I can still see that there are "Assemblies" and "Estimate Assemblies" when in the takeoff. How do I create or modify these assemblies if the button to do so no longer exists?