How to change an existing CfgVehicle without a new pbo

[Sandbird]

I am running an epoch server that includes the MAP_EU.pbo. I just want to change the 3d model of a plant it has:

From this:

    class MAP_c_weed2: MAP_Plants_DNo
    {
        scope=2;
        displayName="G c_weed2";
        icon="\MAP_EU\icon\PG.paa";
        model="\ca\plants2\clutter\c_weed2.p3d";
    };

to this:

    class MAP_c_weed2: MAP_Plants_DNo
    {
        scope=2;
        displayName="G c_weed2";
        icon="\MAP_EU\icon\PG.paa";
        model="\ca\plants2\plant\p_Helianthus.p3d";
    };

The code is already there...every client has the files so it shouldnt be a problem right ?

I tried do this in my description.ext hoping to create a new 'vehicle' with the new model but its not working:

class CfgVehicleClasses {
    class MAP_EUPlants {
        displayName = "MAP: EU-Plants";
    };
};


class CfgVehicles {
    class Static;    // External class reference
    class MAP_Plants_Base : Static {
        displayName = "";
        accuracy = 0.1;    // accuracy needed to recognize type of this target
        vehicleClass = "MAP_EUPlants";
        model = "";
        nameSound = "";
        animated = false;
        simulation = "house";
        cost = 0;
        armor = 300;
        ladders[] = {};
        placement = "slope";
    };
   
    class MAP_Plants_DNo: MAP_Plants_Base
    {
        destrType="DestructNo";
        accuracy=1000;
    };
   
class MAP_c_weed2_Sandbird: MAP_Plants_DNo {
        scope = public;
        displayName="G c_weed2_Sandbird";
        icon="\MAP_EU\icon\PG.paa";
        model="\ca\plants2\plant\p_Helianthus.p3d";
    };
};

What am i doing wrong here?
-Thanks