First: set float level the usual way with floats just touching the float valve.
Second: fit carbs on bike and turn fuel on and check for fuel weeping out of the pilot jet outlets and adjust float levels as required to minimize that.
On a race bike the fuel tap is only on when it's running and it never runs slowly enough to be an issue. On the street with lots of stop lights or really slow riding it would probably be necessary to run a lower fuel level and adjust jetting to compensate.
But to set the float level, just the same as ever.
