install: can't change permissions of /usr/local/bin: Operation not permitted
"Unable to remove symlink. You must have SUDO privileges"
"Unable to create symlink. You must have SUDO privileges"
install: cannot create regular file '/usr/local/bin/tfswitch': Permission denied

Solution: You probably need to have privileges to install tfswitch at /usr/local/bin.

Try the following:

wget  #Get the installer on to your machine:

chmod 755 #Make installer executable

./ -b $HOME/.bin #Install tfswitch in a location you have permission:

$HOME/.bin/tfswitch #test

export PATH=$PATH:$HOME/.bin #Export your .bin into your path

#You should probably add step 4 in your `.bash_profile` in your $HOME directory.

#Next, try:
`tfswitch -b $HOME/.bin/terraform 0.11.7` 

#or simply 

`tfswitch -b $HOME/.bin/terraform`

See the custom directory option -b: