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