Finding CRC collisions for specific divisor
I don't have that book, but I suspect that you are misreading it.

It's always easy to find collisions with CRC, no matter what the divisor (more conventionally known as a polynomial) is.  One easy way is to take the divisor and exclusive-or that bit pattern into an arbitrary place in the message (dividend); as in:

 10011    : Divisor (polynomial)
10101011  : Dividend (message)
11100111  : Modified message

111001110000 / 10011 = 11110110 R 1010


Here, we picked an arbitrary place in the message (starting at the second bit), and bit-wise exclusive-or'ed the divisor there, flipping any bit of the message where the divisor had a 1 bit.  The resulting modified message has exactly the same CRC as the original message.  Also, note that the quotient that we came up with is exactly as the original quotient with the second bit flipped; this is not a coincidence.

Given how easy this is, there wouldn't appear to be an even easier way that is specific to this polynomial.