Open OE6. Click on View -> Layout -> Customize toolbar. There you can add/remove icons you need or don't need. Also, under 'Icon Options' (bottom left corner) you can chose Small/Large icons. If you don't need the icon text you can change them in 'Text Options'. After any change click on Apply, OK. Using the View option you can configure other aspects of OE's display to your needs/liking.
If the above doesn't solve it for you try a 'repair' of IE/OE - click here if you need to know how (assuming you're using WinXP. If not post back if you need help to repair IE in another OS.) HTH, G