You can open the apk with winzip or 7zip or something like that and extract the images that way and put them on your own phone, just select a wallpaper from the gallery or filemanager.
(that should work for static images, for live wallpapers, i don't know)
You can unzip the .apk in your pc and you will find the wallpapers somewhere inside
Thanks a lot! you both were correct!! it´s nice have people who knows a lot as you The wallpapers i was lookong for were not inside CMWallpapers, but i again used 7-zip to extract trebuchet and i found the ones i was looking for!! thanks a lot!!!!