Assuming two tables of 10 seats, your dealers would sit at seats 5 and 6 of each table:
- Right-click on each seat except the "dealer seats" (seats 1 through 4, then 7 through 10, on each table) and select "Make seat unavailable".
- Buy-in your dealers and make sure no other players are bought-in.
- Press "Seat Players" on the Tables tab.
- Press the "Clear" button on the Tables tab. Check only the box that says "Make available all seats marked unavailable". Then press OK. (Alternatively, right-click on each seat and select "Make seat available".)
- Right click on each dealer and select "Lock [name] in seat".
- Buy-in remaining players and seat them. Either check "Auto seat" on the Buy-in window or once they are bought in press the "Suggest Movement" button.