To find a relative date 45 years in the past, you can follow a simple manual calculation process. Start by determining the current year and subtracting 45 years from it. For example, if the current year is 2022, subtracting 45 from it gives you 1977. This means that 45 years ago from 2022 was 1977. This process allows you to accurately pinpoint a specific date in the past based on the number of years you wish to go back by performing a subtraction operation on the year component.