The mod you prolly try to convert to LS 2011, has to be LS2009 Gold ready.

Also the mod name is only allowed to have those letters/numbers: "-",numbers from "0-9", letters from "a - z" and "_".
This can be a reason if your mod does not appear in the store after converting it.

Open your mods .xml (For example 1455XL.xml)
And change this:
<?xml version="1.0" encoding="iso-8859-1" standalone="no" ?>

Into this:
<?xml version="1.0" encoding="utf-8" standalone="no" ?>

Vehicle Types

Code:
<type name="masseyfergussonmf99999xxx" className="Vehicle" filename="$dataS/scripts/vehicles/Vehicle.lua">
It's a tractor, so you need to change it's type from masseyfergusson999999xxxx, into tractor.

<type name="claaslexion79999" className="Vehicle" filename="$dataS/scripts/vehicles/Vehicle.lua">
It's a combine, change it into combine.

<type name="kronecomprimaxx" className="Vehicle" filename="$dataS/scripts/vehicles/Vehicle.lua">
It's a baler, change it into baler.

<type name="halfpipefliegl" className="Vehicle" filename="dataS/scripts/vehicles/Vehicle.lua">
It's a trailer, change it into trailer.

and so on. you basically replace if you got a plough it's name with plough. example: plough1000x23, it needs to be changed into plough.

Sound part:
As theres no fendt in this game, (many modders used some of the fendt sounds back in ls 2009.)
We have to edit this part.

Code:
Before:
<attachSound file="$data/vehicles/steerable/fendt/attach.wav" pitchOffset="1" />
<motorStopSound file="$data/vehicles/steerable/fendt/fendt716out.wav" pitchOffset="1" />
<compressedAirSound file="$data/vehicles/steerable/fendt/compressedAir.wav" pitchOffset="1" volume="1.0"/>
<compressionSound file="$data/vehicles/steerable/fendt/compressorWork.wav" pitchOffset="1" volume="1.5"/>
<aiMotorSound file="$data/vehicles/steerable/fendt/fendt716idleAI.wav" pitchOffset="1" radius="25" innerRadius="4" volume="1.0" />

After:
<attachSound file="data/vehicles/steerable/deutz/attach.wav" pitchOffset="1" />
<motorStopSound file="$data/vehicles/steerable/deutz/agro620_out.wav" pitchOffset="1" />
<compressedAirSound file="$data/vehicles/steerable/deutz/compressedAir.wav" pitchOffset="1" volume="1.0"/>
<compressionSound file="$data/vehicles/steerable/deutz/compressorWork.wav" pitchOffset="1" volume="1.5"/>
<aiMotorSound file="$data/vehicles/steerable/deutz/agro620_idleAI.wav" pitchOffset="1" radius="25" innerRadius="4" volume="1.0" />

If theres no steerable/fendt/ in your .xmls sound part then don't edit it.

modDesc:
First of all change this:
<?xml version="1.0" encoding="iso-8859-1" standalone="no" ?>
<modDesc descVersion="1">

into this:
<?xml version="1.0" encoding="utf-8" standalone="no" ?>
<modDesc descVersion="4">

And add this:
Code:
<title>
<en>Sample mod</en>
<de>Beispiel mod</de>
</title>

You have to add few things here,put <iconFilename> below <description> (iconFilename => store.png of your tractor,description is a example.)

<description>
<en>Converted 1455XL</en>
<de>Converted 1455XL</de>
</description>
<iconFilename>Case.png</iconFilename>
Also add this one below <iconFilename>
<multiplayer supported="true"/>

Should look like this now:

Code:
<description>
<en>Converted</en>
<de>Converted</de>
</description>
<iconFilename>store.png</iconFilename>
<multiplayer supported="true"/>

Final ModDesc:

Code:
<?xml version="1.0" encoding="iso-8859-1" standalone="no" ?>
into
<?xml version="1.0" encoding="utf-8" standalone="no" ?>

<modDesc descVersion="1">
into
<modDesc descVersion="4">

Add this:
<version>1.0</version>

And add this:
<multiplayer supported="true"/>

Also add this:
<iconFilename>Storepictureofthemod.png</iconFilename>

And add the title of your mod
<title>
<en>Modname here</en>
<de>Modname hier</de>
</title>

Script Converting