How do I update my SM-BCR2 Charger so that I can use E-Tube Project?

If you've installed E-Tube Project 4 and you're using the SM-BCR2 charger then you may have gotten a cryptic message starting E-tube Project:

SM-BCR2 recognition. The process is interrupted because the version of SM-BCR2's firmware is old. Connect to the Internet and download the latest version of the firmware.

E-Tube Project tells you to update the SM-BCR2 charger before you can actually use E-Tube Project. Unfortunately, the only way to update the SM-BCR2 is by using E-Tube Project.

The workaround is simple: you install previous version of E-Tube Project, version 3.4.5, and use that to update the charger. Once that is done you can safely use E-Tube Project 4.0.4. Keep in mind that, while most issues shave been fixed, there are still some bugs left in version 4.0.4 and E-Tube Project 3.4.5 may actually work better.

Download E-Tube Project 3.4.5 on the Shimano E-Tube Project site or use this link: api.shimano.com/etube/public/data/upload/published/E-tube_Proj_V_3_4_5.zip