How to connect multiple devices with same I2C address

Well, I ran into a situation where I need to connect 4 SGP30 sensors to a single Arduino.
They all have the same address, meaning I can’t connect all of them to the hardware I2C bus.

But I don’t have SGP30 sensors, thus I use Si7021 just to test if software I2C works. If it works on a single Si7021, then maybe I can conclude that it also works with 4 SGP30s.

The problem is, I came across quite a few software I2C libraries compatible with TwoWire's interface (and modified Si7021 library to use software implementations, of course), none of them work. AFAIK the libraries all stuck with reading from sensor.

Can someone help finding a working library or testing multiple SGP30s connected to one board and getting them working? My deadline is on Saturday, any help is greatly appreciated. Need more information, just ask.