Arduino MEGA2560 and 3 PCA8574PW

Hey there!

I can't seem to find a way to switch between 3 PCA8574PW devices via the I2C communications.
I understand how the basic 1 channel I2C works but can't seem to figure out how to switch between multiple ones.
I've already got the right addresses.

X3 adresses:

Scanning...
I2C device found at address 0x38 !
I2C device found at address 0x39 !
I2C device found at address 0x3A !
I2C device found at address 0x7C !
done

Any suggestions on how to?

Thanks!

You use the address of the device you want to talk to in the wire begin command.