You could use the WDM analyzer before and after the EDFA to calculate the noise figure. Noise would the difference in the SNR before and after the amplifier.
The noise figure itself depends on a number of parameters for a real erbium doped fiber as well as on the input signal. If you don’t have the parameters for the EDFA that would give a noise figure of 6 dB in might be a little tricky without ding a bit of trial and error. However, we do have a component “Optical Amplifier” which you can explicitly set the Noise figure to whichever value you want.
Regards