Looking at the mentioned details, the problem can be addressed via a multistep or a single step approach as per the user criterion.
Once on ensuring the proper constraints using the joints and connections, you can drag and drop the requested joints onto the system name from the project outline to define a boundary condition for the joint.
You can opt for defining the joint boundary condition via the Tabular Data where you can activate and deactivate the joint displacement (eg. specifying it as nil), etc. for respective time or steps.
Defining other boundary conditions by the same method and ensuring your analysis settings are as required for each step would help you get the expected results.
Please refer to the following references for more details-
Hope this helps!