Despite its well-known lack of memory safety, C is still widely used to write both new code and to maintain legacy software. Extensive efforts to make C safe have not seen wide adoption due to poor performance and a lack of backward compatibility. Checked C is an open-source, safe extension to C that addresses these problems. This hands-on tutorial will introduce attendees to Checked C and provide guidance in the use of 3C, a semi-automatic tool that converts legacy C code to Checked C.