Already you have the assembly, now you have to check for contact of each and every part w.r.t other and try to mesh all the components.
I assume you know the loading and boundary conditions. If you give all those things, you can able to run for solution and post processor will solve your problem and give the results.
Hope you will get success in your results
Naga Ranjithkumar A
Not sure if it'd be done if parts are different materials