Update: you can now generate new pair of keys and manage your existing ones via the Security settings page on your account.
From this point forward, documentation is outdated.
Currently your API Key & Secret can be changed by us for your account. It is in our road-map to allow changing the credentials from the Settings page.
Note that when we make the change, any request that uses the previous credentials will stop working.
If you wish to change you API Key & Secret please contact us with such a request. Please include in your request the details of your account and we will update you once the change has been done.