No, you just need to fill freon gas.
removal of the dash is the easiest way of reparing the ac system other than the under hood parts
replace the blend door motor, unless the blend door itself is broken then theres a replacement door or box that need to be installed, this is a big job, the dash needs to be removed to do this job and ac system drained of freon with an ac machine.
The Jeep Grand Cherokee sucks air from the outside via a hole on the passenger side of the cowl. It's under the black plastic piece that runs under the wipers.
The air is then sucked via the blower and blown into the housing where the heater core and A/C evaporator core live.
The blend door is inside this housing as well.
This also depends on if you have regular climate control or the more advanced ATC digital climate control found on some of the Limiteds.
You could possibly take out your glovebox and see if there are any broken pieces going to the door accuator.
Otherwise if it's internal, you'll need to take out the heater/ A/C housing.
To get to this housing, you have to take apart your entire dash, lift the top dash cover off, and then you'll see the housing. You could possibly check for a few thing there.
Most everything there is vacuum controlled.
You have to drain your antifreeze and have your A/C freon discharged (use a professional to capture the freon).
There are 5-6 nuts holding the housing to the firewall. You have to reach these from the engine compartment.
Disconnect your A/C lines and heater hoses. Pull out housing.
This is definately an advanced project, thus the reason for the high pricing.
Hopefully you can get it fixed without having to take this Jeep apart entirely. Try diagnosing with a vacuum gauge if necessary before tearing it apart.
It's under your dashboard, some cars are easy to get to others you have to take off the dashboard to get to it.
I had a Cadillac and was able to reach under the dashboard and move it manually. Look up the actuator for your car online and see what it looks like then look under your dashboard and see if you can see it and move it yourself.