Ok, lets's start.
1. First replace Your current 'Menu.swf' (Example STARHERO Menu or Any Other Menu) with the new 'Menu.swf' you want(Example Motoblur Menu)
2. Then go to Settings/Phone Settings/Language and Change your language (from english to Example german)
3. Then go back and you have a new Menu.
1. For the MyFiles you must replace the Myfiles.swf You want with the Myfiles.swf you already have (Example STARHERO MyFiles to Original MyFiles).
2. Delete STARHERO MyFiles go back to General MyFiles (Pic,Vid,Sou,Oth,Res,Memory...)
3. do not go back to the menu or you will have a white Screen when you re-enter the Myfiles , so put the Original Myfiles in the res folder go back to the menu and enter the Myfiles (Files Icon)
For the gadget I have no Idea