Go to
[HKEY_CURRENT_USER] -> Control Panel -> Mouse -> Razer
The ButtonAssigned1-7 are the buttons one the mouse, to see which is which look them up on the Razer Config.
The value for Windows Button 5 is 00 00 00 04 00 ff ff ff ff
The value for Windows Button 4 is 00 00 00 02 00 ff ff ff ff
So to map left side buttons to Windows Button 5 do this
ButtonAssigned 4+6
Right Click -> Modify -> press delete 4 times -> press 0 0 0 0 0 0 0 4 -> Press ok
The string should then match the one above for Windows Button 5
to map right side buttons to Windows Button 4 do this
ButtonAssigned 5+7
Right Click -> Modify -> press delete 4 times -> press 0 0 0 0 0 0 0 2 -> Press ok
And ofcourse if you want to have Win5 + win4 on one side you just have to edit the apropriate buttons

Ask if you need more help!
The string should then match the one above for Windows Button 4