How?

[Da-Vinci]

Upload the smilies to root/images/smilies via your ftp.

Next got to your ACP in the sidebar on the left near the bottom, you'll see a catergory called Smilies click that, then click Smilie Manager in the new window, click the link called [Show all Smilies], then scroll to the bottom of the page and click the button Add Smilie.

In the new window, go to the option Add Multiple Smilies, set the number per page to what ever you like, I normally do 100 per page. Once you've done that just simply check the smilies you want to use and click the Add Smilies button and that's it job done.