Start by getting access to the GPIO by making a device link 
sudo sh -c  "echo 252 > /sys/class/gpio/export"
ls -l /sys/class/gpio

Then turn the display back on with

sudo sh -c  "echo '1' > /sys/class/gpio/gpio252/value"

or back off
sudo sh -c  "echo '0' > /sys/class/gpio/gpio252/value"

Once you verify that you see GPIO #252, then you can set it to an
output, this will turn off the display since it will output 0 by default

bash
sudo sh -c  "echo 'out' > /sys/class/gpio/gpio252/direction"