you can buy a new keyboard and replace it, this is asus k53 keyboard removal and install guide http://www.laptopwide.com/news/2013/11/1...-to-disassemmble-the-asus-k53-notebook/
replace dvd drive is very easy, please check this link http://www.laptopwide.com/news/2013/09/1...-to-add-a-2nd-hdd-or-ssd-to-dell-studio-xps-164716451640-laptop/