Hi Mateusz,
I have a tuning program that works by inputting values to the stdin_lasershark program. I will upload this this weekend to github.
Currently I use a HP3478A benchtop multimeter to tune these. If at all possible you should use a high precision/resolution and high input impedance. A harbor freight or other low-cost voltmeter will not be very useful.
I have blank lasershark pcbs for sale too by the way. Just shoot me an email if you want one.
-Jeff