I've removed the System Administrator profile from my Partner Community and now I'm locked out from Managing it

Cause

The TaroWorks Partner Community is how the TaroWorks mobile application communicates with Salesforce. In order for a user to have access to the community, their profile must be added to the Community in it's settings. However, if you remove all profiles from the community and click Save, you've effectively locked the community from use.

Solution

Here is a Salesforce reference on how to regain access to the community.