Big weekend for project Sonoma - heater core replacement.
First, I drained the coolant, unhooked the heater hoses, removed the blower motor resistor, battery, and coolant overflow bottle.
One of the bolts for the heater box is inside the underhood HVAC box, so I drilled a hole just big enough to get an extension through, and put the socked on the end, inside the box. I also removed two additional heater box bolts on the firewall and then spray painted the rusty battery tray.
Moving inside the cab, I removed all of the lower kick panels and worked my way up (mostly 7mm with a few 10mm) until I could lay the dash back. Tutorials are available on YouTube, but watch a few because it seems they all leave out something.
After the dash was removed, I got the heater box pulled back and removed and replaced the old heater core.
Foam was cut and installed to replicate factory locations, not just around the perimeter as it shows below.
While I had the dash out, I decided that it was the right time to replace the speakers. I ran to Best Buy to pick up these 4x6" Pioneers. Part Number TS-G460, cost $60.
I then tore the factory speaker connectors off and soldered them to the new speakers.