I used a large tire iron, wedged through the hole against the caliper & it popped right off.
yes
In the gas tank. I have 2001 Echo.
To remove the drum brake from a 2001 Toyota Echo, first, ensure the vehicle is securely lifted and supported on jack stands. Remove the wheel, then locate and remove the drum brake's retaining screws, if present. Gently pull the drum off the wheel hub; if it's stuck, tap it lightly with a hammer to loosen it. Finally, disconnect any springs or hardware that may be attached to the drum before fully removing it.
Remove the immobilizer unit?
2001 Toyota Echo doesn't have a timing belt.
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
Yes
Look in the trunk, there is cover for the brake light, remove and you will have access to change the bulb.
3.5 Liters
To remove the transmission from a 2001 Toyota Echo, start by disconnecting the battery and draining the transmission fluid. Next, remove the drive axles, exhaust components, and any electrical connections attached to the transmission. Support the engine with a jack, unbolt the transmission from the engine, and finally, lower it from the vehicle. Always consult a repair manual for detailed instructions and safety precautions specific to your model.
timing chain.