Change 1 to 0 to remove, or add new techs with =1 . Search for diplomacy_manager . Find:
technology= "production_mechanization"=1 victoria 3 edit save file
country= tag="ENG" name="England" treasury=5000 prestige=120.5 Change 1 to 0 to remove, or add new techs with =1
Example:
Change size to increase population. Search for your country tag, find technology section: Change 1 to 0 to remove
pop= culture="english" religion="protestant" size=50000
relation= first="FRA" second="GER" value=50