Cut the JetPack 4.5.1 to fit the emmc version

After flash the JetPack4.5.1 and all components, it took over 13G of the emmc size, only left 1.3G.
Is there any guide about how to cut the system?

You might want to try this:

Thanks a lot! It really helps.

Thank dkreutz to provide suggestion.

If you are developing a case requiring CUDA or TensorRT, 16GB may not sufficient for rootfs and we would suggest have a custom board with external storage such as NVMe SSD. For putting rootfs to external storage, may refer to
Jetson/L4T/Boot From External Device -

Thanks @DaneLLL , yes, we are running based on CUDA and TensorRT.
We already have the custom board, which only contains a TF card interface as backup.

Is there any guide or whitepaper about how to use a TF card as external storage?

Please check eLinux page in this comment
You wound need to put rootfs on the TF card and then execute script.