How do I Make a Grouped Bridge Model Spin on the Click of a Button?

Hello. I am making a railroad that goes over a decent sized body of water that has boat traffic, and I want to know how I can make the bridge open by spinning 90 degrees from a click of a button. Here's a rundown how it would essentially work.

(Open) Button is clicked Bridge spins (slowly) to the 90 degree OPEN angle Bridge makes it to the OPEN angle

(Close) Button is clicked again Bridge starts slowly moving back to the CLOSED angle Bridge makes it to the CLOSED angle

If the button is clicked again, the bridge opens again, and same thing after its clicked after its opened.

Does anyone know how I can make a bridge do this?

Thank you, -61tar.

You would need to add a primary part to the model, maybe add a part that goes in the middle of the whole model, when primary parts are moved ( with a script ), they move the whole model with it as well.