[lt_eurofighter]

Yes, create a folder called maps in the il2 root folder. Then inside this maps folder create a folder called Okinawa. Don't place anything there. Open then your map Okinawa in FMB map mode. Do the changes and save. Exit FMB and game and look into the
il2root/maps/okinawa/ folder. There are NOW some files inside. If you deleted some trees then you'll find in that folder an actors.static file. That's the modified actors which will contain less trees. Copy the file and place it in
il2root/mods/mapmods/maps/okinawa (create this directory first)
Generally each time you exit FMB map mode and game, copy the files from
il2root/maps/okinawa/
and paste into
il2root/mods/mapmods/maps/okinawa
However it's good to learn too how to add maps or maps variants in your FMB menu, adding lines to all.ini etc.

Thank you sooooooooooooooo much