I need to installed a washroom in my basement , how do I go about it,there no rough in

You rent a jackhammer and take the floor up from the main to where you wish the toilet to set. Click on back when that's done and we'll go to step # 2. good luck, Tom

how do I locate the main the main starts where the vertical stack enters the cement floor and runs over to the house cleanout.
Regards, Tom