Trying to install git on OSX: cannont exec 'git-credential-osxkeychain': Permission denied`

I'm attempting to install Git on my new MBP and am following the documentation @ https://help.github.com/articles/set-up-git. I seem to have hit a snag at the point where it says : `If you do not have the helper, you can download it and copy it to /usr/local/bin` I navigated to /usr/local/bin in terminal and did a sudo wget [link to osxkeychain]. When I try to do a `git config --global credential.helper osxkeychain` I get a `fatal: cannont exec 'git-credential-osxkeychain': Permission denied`. What did I do wrong? Thanks! Tre