(Assuming you've already got the WP CLI tool installed)
In terminal, cd to your site. Then paste in:
`wp plugin install debug-bar debug-bar-timber quick-edit-template-link debug-bar-console --activate`
Next, add the following to your .gitignore file:
```
# Local Debugging Plugins #
###########################
wp-content/plugins/debug-bar/
wp-content/plugins/debug-bar-timber/
wp-content/plugins/debug-bar-console/
wp-content/plugins/quick-edit-template-link/
```
Note that you'll have to re-enable the plugins every time you download a fresh copy of the database from Pantheon, since those plugins aren't enabled (or installed) on the Pantheon site.