How do I get rid of the XOOPS banner at the top of my index.php page??

2 ways to do that:
1. go to system admin -> preferences -> general settings, and set 'use banner ads' to off.
2. go to system admin -> banners, and remove the banners themself.

Herko

Depends on your purpose/goal Do you want ANY banner ads?

To disable ALL banner ads (the simple way):
1) Go to the Administration Menu
2) Go to System Admin > Preferences > General Settings
3) About halfway down, you'll see the option "Activate banner ads?" Select No.
4) Click on the Go! button to save your changes.

To disable ALL banner ads (a little more advanced):
This step requires knowledge of HTML and an understanding of XOOPS Themes. Read the info on Theme hacking in the XOOPS Wiki for more information and details.
1) Find the text in your theme.html (or similar html document in your XOOPS theme).
2) Open it in your favorite HTML editor (whether online or offline)
3) Remove the code that references XOOPS Banner, typically found towards the top of the theme.

To disable JUST the XOOPS banner, but leave other banners enabled:
1) Go to the Administration Menu
2) Go to System Admin > Banners
3) For any banner under "Current Active Banners" with a client name of XOOPS, click on Delete.
4) You can also delete XOOPS as a client if you so choose.