My truck was stuck in 4L. Shift on the fly system and chased my tail for a week. I went through this and other forums and YouTube to find a fix. I did all the common stuff and not so common. My transfer case was stuck in 4L. I was not able to manually move it. Here was my fix. I took the new transfer case motor and electrically moved it with the truck battery. One wire on the positive side, one on ground. On the motor, touch one wire to the large orange pin and the other to the large yellow pin. Let the motor move over to the 4L position.
Make sure the switch in the cab is in 4L. Install the new motor and reconnect the battery. Start the truck, put it in neutral and turn the switch to 4H. Clunk clunk clunk...back up ten or so feet. Then shift from 4H to 2 like you normally would.
I had tried to manually move the transfer case (with vice grips), and it wouldn’t move out of 4L. Be careful you don’t shock yourself. I used an old extension cord to “jump” the transfer case motor with.

There are 2 orange wires and two yellow- make sure you use the big ones.

Inside the transfer case motor plug.

 

An easier fix would be jack the truck up, off all 4's, and rotate everything so that the gears mesh to let you use pliers to put it in 2H in the transfer case.

But your way isn't wrong, it's just time consuming.

 

It took less than an hour. I don’t have a jack or stands.

 

Fair enough. At least you got it fixed.