How do I alter an existing template?

[lwhitb1]

I'm currently attempting to install the v3 arcade hack, but I am stuck on this installation step:

Make the following alterations to these existing templates, and save them.

==============
postbit
==============

Where can I find postbit?

I checked the directories on my server, and didn't see it. I am knew to vBulletin, so forgive me for the newbie question..

Thanks in advance

[Zachery]

I'm currently attempting to install the v3 arcade hack, but I am stuck on this installation step:

Make the following alterations to these existing templates, and save them.

==============
postbit
==============

Where can I find postbit?

I checked the directories on my server, and didn't see it. I am knew to vBulletin, so forgive me for the newbie question..

Thanks in advance
AdminCP > Styles & Templates > Style manager > find the postbit category, expand > edit the postbit or postbit legacy template if your using vB3