dc42:
That should have been exactly the right thing to do. Try doing it again, but also reduce REQUIRED_FREQUENCY in case 1MHz is a little high, given that you have the resonator still connected and a 1.5K resistor in series with the clock signal. As the Arduino you are using to generate the clock is also 3.3V, I think you can also safely try it without the 1.5K series resistor. What you are looking for is a signal on CLKOUT at a reasonable frequency.
So what you're saying is that I should lower the REQUIRED_FREQUENCY to a number until CLKOUT starts showing a steady clock? Right now, at 1MHz, the analyzer doesn't detect anything on CLKOUT at that speed.