How to resizing the root FS (manual method)

Hello everyone.

Please tell me what other options are there to expand the root partition besides the one indicated in the wiki. The wiki indicates a working option https://openwrt.org/docs/guide-user/additional-software/extroot_configuration, but I would like to know what other options there are. Please write how you did it. I ask you to write the commands so that your method can be tested. Or provide a link to the source with the commands.

so that I could get a result like this:

root@OpenWrt:~# df -Th
Filesystem           Type            Size      Used Available Use% Mounted on
/dev/root            ext4           58.9G     19.7M     58.8G   0% /
tmpfs                tmpfs         494.1M   1020.0K    493.1M   0% /tmp
tmpfs                tmpfs         512.0K         0    512.0K   0% /dev