Remove finder from Dock

Open (you need root permissions):

/System/Library/CoreServices/Dock.app/Contents/Resources/DockMenus.plist

Add a new subsection to “finder-running”:

<dict>
    <key>command</key>
    <integer>1004</integer>
    <key>name</key>
    <string>REMOVE_FROM_DOCK</string>
</dict>

Kill the dock:

killall Dock

Then right click on Finder icon in Dock and click on “remove from dock”