Dually wheel simulator question

[Tx Firefighter]

I am building a dually right now and have a question about wheel simulators.

How are simulators bolted on ? Is there a plate that goes on underneath the lugnuts or what ?

I want this look....




It looks to me that he has combined late model center caps with wheel simulators.

Center caps:


I know about the special outside threaded lugnuts that these centers require, and I already have a set coming in the mail.

Will I need to do anything special to use these center caps over the simulators ? Or, can I just hold the simulators in place using any lug nut and then run my newer centers instead of the normal centers included with the simulators?