can anyone tell me how to turn off my change oil light on my 2004 tahoe

GM Oil Life System
Press the fuel information button until ENGINE OIL LIFE
appears in the display. The GM Oil Life System shows
an estimate of the oil’s remaining useful life. It will show
100% when the system is reset after an oil change.
It will alert you to change your oil on a schedule
consistent with your driving conditions.
Always reset the engine oil life after an oil change.
To reset the Oil Life System use the fuel button to reach
the ENGINE OIL LIFE screen and then press and
hold the select button for five seconds while ENGINE
OIL LIFE is displayed. OIL LIFE RESET will appear on
the display for 10 seconds to let you know the system
is reset.

Its also in your owner manual. If you don't have one you can get one in PDF format off of the GM website.

can anyone tell me how to turn off my change oil light on my 2004 tahoe

The correct method to reset the oil life monitor on your 2004 tahoe is the same as my 2000 silverado ... with the ignition switch to run engine off depress gas pedal fully to the floor 3 times within 5 seconds...then engage starter and when engine starts the oil monitor will flash ...this then is reset..If this does not occur repeat,clear floor mats or what ever so that pedal does fully depress..

Thats funny because I copied and pasted it directly from the PDF owners manuel. The 2000 according to the PDF owners manuel is done how you described. The 2004 uses the buttons on the steering wheel?

http://i83.photobucket.com/albums/j293/airjer/AF%20Stuff/ownersmanuels.jpg