Where is the blend door actuator in my s13? Heater stuck on floor mode

[v30magna]

My s13 vent system is stuck on floor mode. I searched and found out I need to check the blend door actuator, but I can't find anything about how to get to it. Where is it, how do I get to it?

[kruked]

It's right behind the radio

[v30magna]

Thanks kruked