@niek said:
Is there a way to override the default pin?
Yes and no. And maybe you don't have to
Have you tried connecting both sensors to the same pins? That might work without you having to do anything. If that doesn't work, read on...
The Adafruit BH1750 and BMP085 libraries do not support configuring which device on the i2c bus to "talk" to. There is an old pull request to add support, but it hasn't been added to the official code. You could download the fork.
Both sensors communicate using i2c, and it is possible to connect multiple i2c devices to the same i2c bus.
The two Adafruit libraries use the Wire library underneath. The Wire library handles i2c communication. So if you use the Wire library directly, you can connect both sensors to the same pins and follow the instructions here. Doing that will probably require some programming skills though, since you will need to do the stuff done by Adafruit's libraries manually.
An alternative might be ut use Soft SPI to use a different set of pins, but I think that would require more work than using the Wire library.