Remove Project Server Completely from SharePoint 2016

My SharePoint 2016 environment have MS Project Server. 

I want to remove MS project Server from my environment completely and cleanly. I want to remove its database schema, service application, services  and all other traces from SharePoint farm. 

Currently, I have deleted service application and stopped service. But i want to clear content database with MS project tables e.g. MSP_ASSIGNMENT_BASELINES, MSP_PROJ_CUSTOM_FIELD_VALUES, etc.. 

I read in many sites that it is not possible to remove MS project completely. Is there any manual way to clean SharePoint content database. Can i delete tables directly from database?