The following can be used,
i2c = PimoroniI2C(sda=(4), scl=(5))
in place of
i2c = PimoroniI2C(**PINS_BREAKOUT_GARDEN)
There are other options to change the baud rate and specify the i2c0 or i2c1. You have to look at the pimoroni_i2c.cpp file, and do some guess work. Not something I have had to do just yet.