There will eventually also be a video tutorial available here:
In this guide I will show you how to move your root file system from the SD card to a SSD drive. At the moment of writing this guide, booting of a USB storage drive is not possible with the Raspberry Pi 4. This does not mean that we can't still use the speed and reliability of a SSD. We can do this by using the SD card for the initial boot, but then point to the SSD as root file system.
This guide contains 3 seperately usable guides, so I will split them up. This way it's also not a verty long read. :)
Go to: Prepare SSD
Go to: Copy file system
Go to: Resize SSD
I had to use a couple of sources to piece this one together, but special thanks to the people that have already shared their experiences.
Delete and format partitions (followed until step 9):
https://www.tomshardware.com/news/boot-raspberry-pi-from-usb,39782.html
Easy SD to SSD file copy:
https://www.element14.com/community/community/raspberry-pi/blog/2019/08/30/quick-sd-to-ssd-on-the-pi-4
Resize partition (Step: Reduce a Partition and Filesystem):
https://geekpeek.net/resize-filesystem-fdisk-resize2fs/