Eastbound buses start their trips at Queens Quay West and Bathurst Street and proceed:
northward along Bathurst;
eastward along Lake Shore Boulevard West;
southward along Dan Leckie Way;
eastward along Queens Quay;
northward along Bay Street;
eastward along Front Street West;
northward along Yonge Street;
westward along Wellington Street West; and then
southward along Bay, stopping beside Union Station, south of Front.

Westbound buses start their trips on Bay Street, south of Front Street West, then proceed:
southward along Bay; and then
westward along Queens Quay West to Bathurst Street.

510 Spadina:

All southbound streetcars end their trips at the loop at Queens Quay West and Lower Spadina Avenue. All northbound streetcars start their trips at the same loop. A shuttle bus service will replace streetcar service along Queens Quay east of Spadina.

You can see a map of the detours here. (.pdf)