This video demonstrates replacement of the front door speakers with an aftermarket speaker in a 2008 Chevy Impala. Parts list below.
2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Chevy Impalas are all identical, and this process will also work for many other GM vehicles in the same generation.
Referral links for all parts in this video:
JVC CSV628 Speakers: amzn.to/2daiets
Speaker Wiring Adapter Harness: amzn.to/2drvE5P
Scosche Speaker Adapter Frame: amzn.to/2drwDTB
Boom Mat Speaker Baffles: amzn.to/2djUX9l