Nissan Repair: 2003 altima 2.5 coolant change, 2003 nissan altima, nissan altima

Question
What is the proper way to change the coolant in my 2003 Nissan Altima 2.5 (4cyl)?
I was told in order to safely change the coolant that I have to open an air bleader plug on the engine to make sure there is no air trapped in the engine. Is this true? If so....where is this plug found? and how do I remove and replace it safely?
Thank you.

Answer
Lou,

The bleeder is to get air out of the system once you fill it back up.  Yes, it will expedite the coolant coming out but it is for filling.  Remember to never backflush the system so you do not over-pressurize the system.  Just drain and fill with clean water a couple of times to get all the old coolant out.  Then fill with a 50/50 mix of antifreeze and demineralized water.  Check the upper hose and follow it to the engine to find the small bleeder screw.  Open it after you fill the engine (engine running) and close it after you see coolant weep out.  If you want the procedure from nissan go to nissantechinfo.com