Although there are some programs that allow us to modify file Keys.xml used by Glider, there are many corrupted with viruses in the internet. Since it is a pain in the ass to edit it manually I decided to make another one - clean and specially for MMowned community. The links to the application may be found in the bottom of the post. Let's start.
Glider Key Mapping Editor by Razgul for MMOwned.com community
That name rox! :P
1. Starting up.
To start up the application, place the exec file together with file Keys.xml in the same directory. If the file Keys.xml is missing the application will not start and NO message about that will be shown (so put the application together with Keys.xml).
2. The GUI.

The GUI is simple and friendly to Glider user I think. It's divided into 2 parts: table and editing menu. In the table we may see 5 columns: Class, Action, Bar, Shift and Character. Class and Action are obvious. Bar tells us what bur is used by Glider, Shift what addition(None/Alt/Shift/Ctrl) key and Character what key. Editing menu allows us to change the values of Key Mapping.
3. Editing.

The Bar value has just been changed.
There are 3 types of possible edition:
- Bar - allows us to modify which bar(Combat/Rest/Indifferent) shall be used.
- Shift - determines if simultaneously None/Alt/Shift/Ctrl shall be pressed.
- Character - determines which key shall be connected with certain action.
The values can be only changed by using the editing menu. By clicking on the table determine which row is going to be edited and its values are automatically imported into editing menu. To change Bar/Shift choose possible options from combo boxes. Simply write latter(only ONE, or specified name of key) into text field to determine the Character.

The Character value is being written.
When you are done press "Export". If the operation has succeeded the following message will appear.

Otherwise error message will be displayed.
4. Other comments.
Be aware NOT to use application while WoW is running. It contains "Glider" in it's name so...
The application imports "Actions" from the file Keys.xml. Therefore if any has been removed manually by the user it will not be shown in the table. In that case put them back or generate new file Keys.xml(useing Glider).
Because of Glider notation if there is more that 1 char in Character text field it will be saved as VK(not as Char as usually). Unless the value to be saved is "Undefined"(than its gonna be written as Char). Just so you know.
The application is entirely my(Razgul's) work and all credits goes to me! Weeeee! 
In case of any suggestions, questions or bugs found priv me please.
Sorry for bad English - I'm still learning.
4. Download and scan.
Scan: Virustotal. MD5: 7ebce56987cefa063e899e3b2381d764 Win32.Malware.gen (suspicious)
It's written it finds Malware. I believe it's because program is able to read and save file.
Download: GliderKeyMapper.rar
GliderKeyMapper.rar - Glider Key Mapping Editor - Dedicated Web Hosting Service
Thanks for reading and I hope you will find it useful.