This is a major repair requiring the removal of the intake manifold, exhaust manifold, and heads. This repair can only be done by a professional with the proper tools and training. No way can anyone tell you how to do this on a website. If you want to DIY, then purchase a Hayne's Repair Manual for your car.
How to Replace spark plugs on 2004 cadillac deville Sls with 4.6 v8 engine
approx $600(100 part 500 labor)
The 2004 Cadillac CTS has a V6 engine.
The 2004 Cadillac SRX has a V6 engine.
The 2004 Cadillac Escalade has a V8 engine.
The 2004 Cadillac Escalade-ESV has a V8 engine.
The 2004 Cadillac CTS-V has a V8 engine.
The 2004 Cadillac Escalade-EXT has a V8 engine.
Break your 2004 Cadillac SRX with a sledgehammer.
The 2004 Cadillac SRX has a 3.6 L base engine size.
The 2004 Cadillac Escalade has a 5.3 L base engine size.
cost to replace a head gasket