What are the services that MROs provide for corporate jets (private jets)?
In general, the MRO services for corporate jets includes, but is not limited to:


Aircraft major and minor inspections and overhaul
Aircraft defect rectification and trouble shooting 
On-site defect rectification (away from base).
Compliance of regulatory directives.
Replacement of avionics units.
Aircraft engine maintenance.


The costs associated with these activities will vary depending on the model, location and aircraft condition. If you want actual costs, it would be best to contact the service provider directly.