Find your "Profiles" icon. This is where you can change all of your sound settings. Once you click on the icon if you scroll down and click "advanced" it'll take you to a screen where you can click on the profile you want to edit "normal, vibrate, loud..etc" and if you click on the profile you want you can change all the sound settings for everything; text/phone/email/MMS/applications...etc.
Hope this helps.
You'll find the options for changing the vibrate in the same area. Don't be afraid to explore the advanced profile settings. So when you see the profile icons (loud,normal..etc) scroll down to "advanced" then click on the active profile you want to edit then scroll down till you see "phone" and click on that. From there you'll be able to change all the settings for your incoming calls, for no vibrate you want to make sure the first line says "tone" only. Not "Tone+Vibrate". Like I said don't be afraid to explore this... any sound settings you ever want to change are going to be inside that "advanced" option.