Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi, I am Mike, welcome. I'm reviewing your question.
Did you use the tool like in this picture?http://ww2.justanswer.com/uploads/schmainkman/2010-01-30_235554_gram.jpg
this tool, http://www.ss396.com/mm5/graphics/00000001/TRIM-02.jpg
Once you remove the door panel, then the rod from the door lock cylinder, usually there is a clip that is you stick a long thick screwdriver in there you can pry the clip off, then the lock cylinder falls right out the outside.
Here are the instructions,