Could I make changes to a bootable Ubuntu ISO by booting into it, making changes within the OS, and re-exporting the ISO?

Suppose I have a bootable Ubuntu ISO. I would like to make several changes to the image at the OS level. The changes I want to make include changing the default user password, as well as a few other OS settings. Could I write the ISO image to a removable drive, boot into Ubuntu from this drive, make the changes within the OS, and then create a new bootable ISO (with my changes) from this removable drive? Suppose that the image I’m starting with already has some packages installed and custom modifications done, so starting fresh from a new Ubuntu ISO isn’t an option. Would my approach work? Or

Question by ivorysoap on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.