PiShrink

Dumping existing image 
 Install cockit on Raspberry Pi 
 sudo apt install cockpit 
 Shutdown Raspberry PI, take out the SD card, and connect it to your PC. 
 The boot - and  rootfs -partitions were automatically mounted at the mentioned mount points. Before you proceed, unmount them with : 
 umount /dev/mmcblk0p1
umount /dev/mmcblk0p2 
 Now we copy the contents of the SD card to our file system. 
 sudo dd if=/dev/mmcblk0 of=/home/alang/worktmp/PiShrink/my_rasp.v2.img bs=32M 
 Download the PiShrink 
 https://github.com/Drewsif/PiShrink  
 Now invoke the script by typing: 
 sudo ./pishrink.sh my_rasp.v2.img 
 Flash the image to the SD card 
 
 BalenaEtcher 
 SD Cards and Writing Images