Here are the steps to get a second passport & citizenship through your ancestry:
Step #1: Determine if you have ancestry that could lead to citizenship by descent​
Step #2: Determine if you are eligible​ which usually requires “uninterrupted” lineage...
Step #3: Gather all the required documents​ such as birth, death, and marriage certificates from local records in your ancestral country.
Step #4: Submit your application​
You may want to start by contacting the country’s embassy. You will usually need to attend an in person interview, and the wait for an appointment could be substantial.