# Update the Raspberry pi
sudo apt update && sudo apt dist-upgrade
# Open the config.txt file in /boot/
sudo vi /boot/config.txt

# Find the part that says
#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Insert following for 1400 mhz overlock
#Overclock 1400
arm_freq=1400
core_freq=525
over_voltage=6
gpu_freq=700