How to connect two water level sensors (10cm) to Base Shield V2.0


I have a Grove water level sensor (10cm) I2C and a Grove Base Shield V2.0. I have the code for the level sensor from your site, I want to connect another water level sensor to the Base Shield but I don’t know how, they are not plug and play.
I know it involves changing an address but don’t don’t know how to do this. The example on your website shows a buzzer and a button, so an input and output device, and not an I2C connection I have two inputs.