Adding-Removing software with Calculate Linux

How can I add or remove software with Calculate Linux 12 beta, I install on live usb, and i would, for exemple, to install thunderbird 13.

Thank you

I found this link:, but it seems complicated, it seems like we have to use terminal to add software. I am not realy a nerd, but i like the look and feel of Calculate Linux 12 If your flash memory size by more than 2 times the size of the image distribution, you can add software to it, creating a new squashfs image file. You can also change the ISO image. This guide is perhaps a little out of date and for the 12th version of the distribution.