I see no way to set the tone to search, unless You know it the only choose is none.
This is not the Fire Tone search I'm wanting to know about.
Is there any easy way to do this, with FreeSCAN?
Sure. (Tom, nd5y, typed faster

)
Just click on the field for "Tone" (PL/CTCSSS or DCS) & hit an
S. The "Search" is right in the middle, between where the PL tone values end & DCS code entries begin.
If you have a number of them, in the same group, to change to the same value at one time (PL/DCS, Modulation to NFM, whatever), highlight all of them at once. If they are consecutive, hold don the <Shift> key and click on the first and last one to highlight all. If not consecutive, press & hold down the <CTRL> key, and click to select all the channels for your group update.
Now, still holding down the <CTRL> key, change one of the fields that need updating, on one line. Still holding down <CTRL>, clicking the same field on another of your highlighted lines will change all the selected lines to the same value.