Im picking up a 2006 trailblazer this weekend it a slight rebuilder,battery needs a jump start to get going has been sitting since january, is there any thing special i need to do before disconecting the old battery, so nothing get gufffed up when i go to restart it?? is this one of the gm products that you have to put a code into the radio to get the vehicle to start.

Unless the radio was locked, you should not need to put in a code. Other than that, it is straight forward.