GMC Repair: Changing trans. fluid, correct steps, filter change

Question
QUESTION: Hi, I am simply trying to save $ by changing the transmission fluid on a 2004 2W drive Yukon.  Purchased used with 85,000 and not sure if the fluid has ever been changed.  Dealer says the filters are permanent.  Can you tell me the necessary steps for changing and/or flushing?  Thanks.

ANSWER: i would reccomend flushing the system, it can be done at the dealer or an oil change facility

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QUESTION: Sorry i was not clear in my question that i am wanting to change and flush myself to save the Ridiculous $180 charged by the dealership. I am mechanically inclined, just want to make sure i follow the correct steps.  Would you mind listing the steps?  Thanks.

Answer
to properly flush the system you do need a special machine that power flushes the system.  You can however remove the trans pan and filter, and replace the filter and gasket, however you will only remove approximately 5 quarts of the old fluid.  With a proper flush you will take out 16 quarts.  I would go with a flush, if you shop around you might find it for cheaper than $180 I know my dealer does not charge that much.  Or you can just do the fluid and filter change.