Locked library folder on external drive

Hi, I have a locked user Library folder on an external hard drive. I don't want to reinstall it as my main user library folder but I do want to rescue some email folders off it. The file is called Former Library on a hard drive called A1 Columbia 2020.

However, when I try the sudo chflags command it refuses to work and returns this instruction.

iMac ~ % sudo chflags nohidden/Volumes/A1\ Columbia\ 2020/Former\ Library

returns

usage: chflags [-fhvx] [-R [-H | -L | -P]] flags file ...

Help appreciated!

Will