How does i2c_write work?

Thanks to the bildr website and members of this forum, I finally am communicating with my MLX90614, the Melexis IR temp IC, using the i2cmaster library. For my project, I need to change the default programming of the MLX90614. When I write to it's eeprom memory, nothing changes. Apparently I also need to send the right PEC data.

So, a few questions. Can someone direct me to examples of using i2c_write to write multiple bytes, formats, etc. and second; I don't understand how to figure the PEC, if I need to even have it? Actually, there are a lot more questions but I'm ahead of last week.