How to remove the uncompleted update in Mac OS

Hi

the problem began from when I tried some times update my Mac OS to Catalina(in apple logo > system preferences > Software update) , but I got several errors like network lost or request time out, but the real problem is that my disk filled with the useless update files that I don't know where are they?(the picture shows that)

at the other hand I can't reinstall my macOS (Mojave form recovery boot)

because it take me several errors like previous in updating to Catalina

thank you for your help guys BTW