A quick NG search makes it "look" pretty easy - what are going to do
with the other 6 1/2 days of your week off?

1. Disconnect battery and drain system to level below heater core.
2. Disconnect and plug heater hoses from the core.
3. In passenger compartment, remove 4 screws attaching heater core
access
cover to plenum assembly and remove access cover.
4. Pull heater core rearward and downward.

Disconnect the two hoses at the firewall under the hood, remove the
carpeted cover under the dash on the
pass. side, remove the plastic drain tray under the core, push the top
tubes
of the core in through the firewall and lower the old core out.