Addressing 23017/4051 using I2C Serial Interface & PROGMEM

All of those compiler errors will come with a line number at the start that tells you the exact line the error happens, so you should look on that line. Don't worry too much about the number of errors, as the first few often cascade a flurry as the compiler gets confused about where it is. Just focus on the first one and work your way down the list.

Also, make sure that the example code is compatible with the version 1.0 IDE as there were some changes at that time that cause all sorts of errors.