Hello!
I am able to add an item to the dock with this command:
defaults write com.apple.dock persistent-apps -array-add '<dict><key>tile-data</key><dict><key>file-data</key><dict><key>_CFURLString</key><string>/Applications/Preview.app</string><key>_CFURLStringType</key><integer>0</integer></dict></dict></dict>';killall -HUP Dock
Now I would like to be able to remove the same item from the dock, but I can't seem to figure out what needs to change in the command.
Once again, thanks for your help!