You can register to vote online (in English or Espanol), if you have an Oregon driver's license or State ID card. You can also use the online system to make changes to your existing registration, like changing your address or party membership. Go to: https://secure.sos.state.or.us/eim/vr/register.do?
Click to download the Oregon Voter Registration Form (English) or the Oregon Voter Registration Form (Espanol) in PDF format. Fill in the little circle next to "Independent Party" or "Partido Independientero." Fill in the rest of your information.
If you are already registered and are simply changing your registration to the Independent Party, you do not need to send in any of the ID materials mentioned on the form (driver's license, etc.).
Mail it to your county election office. The second page of the attached file provides the addresses. Remember the 44 cent stamp! You do not have to mail in the second page.