What's involved swapping the hatch microswitch?
 

My hatch has stopped opening with the key. Switch up in the drivers foot well works fine, looks like a bad microswitch. (I have an '89)

Part is pretty cheap, $20. Is it a plug n play or will I need to solder the new microswitch into place?

Clean out the switch and measure the contacts. They get gummed up with dirt and water.

Otherwise, the switch is easily replaceable. The wires have connectors, so no soldering needed.

If it opens with the switch up front but not the key, it's not the microswitch.

There is a little plastic clip that holds the unlocking rod to the back of the lock cylinder, when that clip breaks, the unlocking rod will fall out.

Clip part number 999.166.054.02 (for 1988 - on)