The first step is to disconnect the negative battery cable before you start working on the antenna.
- Remove interior side panel under the dash in the front passenger area. Use a screwdriver to discover where the antenna comes into the interior. Disconnect the coaxial cable from the antenna and the radio.
- Disconnect the antenna from the power supply. It should be by the fuse box on the driver’s side under the dash.
- Loosen the nut on the base of the antenna on the exterior of the vehicle. Protect the fender by placing a clean cloth down.
- Use an open ended wrench to remove the nut from the antenna mast. Use an open end wrench to unbolt the antenna from the side wall. Pull the antenna through the fender opening.
- Remove the antenna and look at the opening to ensure there is no rust or other damage to the opening.
- Replace the antenna and feed it up through the fender hole.
- Reattach the parts in reverse order.
- Reconnect the battery and test the antenna.
It is not hard to replace the antenna on your Toyota Sienna or FJ Cruiser. When you need the replacement mast, use OEM part 86309-0C020.
It can be found here.