Step 1:You can install the touch driver for 3.5″touch screen on an existing system, but it just supports raspbian and ubuntu system. Raspberry Pi must be connected to the Internet,and you can control it through ssh,vnc, Remote desktop or the other big HDMI display;
Step 2:Open the command terminal,Enter the following commands to download the 3.5″touch screen driver;
sudo git clone https://github.com/kedei/LCD_driver
Step 3:Change file permissions;
sudo chmod -R 777 LCD_driver
Step 4:Enter the folder;
cd LCD_driver
Step 5:Install the driver, RaspberryPi will auto reboot ;
./LCD35_show