You will need ads to do it and send spend credit request via support ticket. Here are some info that might help you about the ammount of ads you will need.
See below table for existing Kaho Horn customizations
$5 Change an already customized Kaho into another existing customization (must include username and password)
$15 Change an already customized Kaho into a non-existing customization (must include username and password)
$40 Change an uncustomized Kaho into a non-existing customization (must include username and password)
$30 Change an uncustomized Kaho into a existing customization (must include username and password)
Services
hope it will help!...