From the 7000i as well.anything after the 8000i with cards
I must have had a different EOS 5 as mine had AEB! It is activated by a multi-function button on the back. The last button on a row of 4, if I remember well.EOS 5 has no auto-bracketing feature but it's not a task to set this manually, as you would do with a camera with no on-board meter.
Here is the manual: http://www.cameramanuals.org/canon_pdf/canon_eos_5.pdf