http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
In the red cover on the positive terminal of the battery.
see link
See related link
yes
In the gas tank. I have 2001 Echo.
2001 Toyota Echo doesn't have a timing belt.
http://groups.msn.com/Sorensonbrian/fuelfilter.msnw follow this DIY
http://pdftown.com/2000-2002-Toyota-Echo-Service-Manual.html
Look in the trunk, there is cover for the brake light, remove and you will have access to change the bulb.
3.5 Liters
Which bulb are you trying to change?