The easiest way to complete these challenges requires installing certain tools:
Pwn tools:
$ sudo apt-get install python3-pwntools
Gef GDB:
$ wget -O ~/.gdbinit-gef.py -q https://gef.blah.cat/py
$ echo source ~/.gdbinit-gef.py >> ~/.gdbinit
Ropper:
$ sudo apt-get install ropper