Add a smiley set
From Online Manual
Extra smiley sets can be added by using the Package Manager, or you can add them manually.
| Multiple Smiley Sets: Avoiding Problems
If you install more than one smiley set, it is advisable to make sure that each set contains graphics files with exactly the same names. This is because if some of your members are using different sets of smileys, they will not see each other's smileys if the files do not have the same names. Alternatively, if one image appears in one set, but not the other, they will encounter broken smileys.
Adding a Smiley Set Using the Package Manager
If you want to add smileys to a set, edit their code, placement order, or the places where they are displayed, for example on the post screen, as a pop-up, or hidden you need to check Enable customized smileys on the Settings page of the smiley section.
Adding a Smiley Set by Creating a Directory
The other way to add a smiley set is to create a directory inside your forum's "Smileys" directory. First, give it the name that you want it to have, then upload all the actual graphic files for your smileys into that directory.
Next, go to Admin > Smileys and Message Icons > Smiley Sets and click on New Smiley Set. Select a name for this smiley set, the logical choice being to give it the same name as the directory you created. Click New smiley set and you will see "URL:" and, to the right of that, a requester. Use this to select the set's name.
Check the box labelled Import smileys already in this directory: and, if you want to make this set your forum's default set, check the box labelled Default smiley set:.
When you click Save changes, your new smiley set should be recognised and installed.