I thought out this “simple” way of “creating” your own Windows Media Player Skin, without the need of knowing any complex xml and java script programming knowledge.
What is a Windows Media Player Skin?
It is nothing but a zip folder saved as wmz (Windows Media Player Skin format),which include a xml file, a Java script file and lot of image files.
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How we will proceed?
Technically, we will do a reverse engineering of a wmz file and replace or modified the image files, then rebuild it. In this way, very complex skins can be modded and customized.
Step 1
Download and/or select a WMP skin of your choice; including those have custom startup animations or some complex things. It would take even months to develop such a skin if you go for proper writing of the scripts yourself, in order to make it bug free.
I am using Age of Mythology WMP Skin by Skin Factory to make this tutorial, however, you can select any skin. It has an animation at startup (the door opens).

Step 2 : The reverse engineering
Open it with Winzip or WinRar or any such program. I will use my WinRar 3.80 to show you the process.
You can see a lot of image files here. Dont look it now! we should proceed to have a more close look on these!
Click the “Extract To” on the top the Window:

Change the file name and destination path in the prompt window:

Hit enter or click OK button.
You will get a unzipped folder:

With this, we have ended the Step 2.
Step 3 : The reverse engineering
Now, have a look inside the folder:
Follow these steps:
1. Modify each and every image files in Photoshop or Corel Draw or Gimp or FireWorks. You must keep the size, position of buttons in the same place. Save it in the same format (i.e. Bitmap or BMP in short) and file name (i.e. you will replace the images one by one).
2. Open the xml file (will look like a script icon: right lowermost file icon in the above screenshot) in notepad:
Its better to avoid any change, if you are not an advanced user (so, no need to open it in that case). In case you think to change something, keep a backup of this xml file. Use “save” from file menu to save any changes.
3. You will find another file, whose icon will look like Windows Media Player theme icon. Open it with notepad too:


Its better to avoid any change, if you are not an advanced user (so, no need to open it in that case). In case you think to change something, keep a backup of this file. Use “save” from file menu to save any changes.
Step 4: Re build the theme
Inside the folder, select all the (modded) files by pressing [Ctrl] and [A] from keyboard:
Right click over any file and select to use the WinZip/WinRar or other similar compression program:

Follow the above screenshot very carefully.
-Change the Archive format to ZIP (not RAR or other format)
-Change the Archive name and extension. The extension must be “wmz”, instead of “zip”.
Hit Enter or click OK.
Done!
You will get this wmz / WMP skin file of your own!

Check whether its working by double clicking it: it should be!
Step 5:

Note for Advanced users:
The key behavior lies in that two files: so, you can add or delete other parameters to add or remove its behavior further.
Note for all users:
1. We are providing this tutorial in good faith that users will use this tutorial ONLY for modifying the skin for personal use or educational use. I or this website is not anyway responsible for any copyright violation.
2. Do not modify the “Copyright” texts inside the key files (xml, CSS or Java script; which ever applicable).
3. You can use the word “Modded by yourname” with the filename for your own use. Always mention the original creation with proper hyperlinks in case of Point number 5 described below.
4. Its better to ask the original copyright holder before distributing (even for free) it to others.
5. Point 1 to 4 is not applicable if 1) Its not copyright protected or 2) Distributed as open source file.