EDIT - after typing all the below info I re-read your post (sorry half asleep) and it sounds like you just want to change the actuators? You can do that without removing the dash or HVAC box. Did you have other reasons to remove it? It can be tricky to do the recirculate actuator with the dash in place but even that is do-able, just tight. With the dash out, it would be cake. No need to remove the HVAC box generally unless it's broken or you want to do a really thorough cleaning of the crud that can collect on the air inlet side of the evaporator core. With all that said, of course you'll be opening the system and letting the refrigerant out...
There's one bolt from the interior side, 10mm, use a long extension to reach it. It's near the top hump of the evaporator core, towards the left (driver side). You can get a feel for where it's at by looking at the engine compartment side as you'll see the end of the bolt poking through a weld nut on the firewall.
There's numerous 10mm screws (they just go into the plastic housing) on the engine compartment side; they're black and have the larger captive washer so they do stand out. A couple of them are hidden - you'll need to remove the coolant reservoir to see them all. At least a couple of them are in the middle of the firewall behind the engine. One is hidden a little bit by the passenger side cowl drain duct. I used to remember how many in total there were, it's around 6; sorry but I've forgotten over the years. There may also be one nut on the engine side to remove near the heater core lines.
Richard