The best that I could find was White 1. Compared to simply exchanging 5 for 6, this is two points better in sente. Since it threatens the corner group's life it is absolute sente for White.
In the upper right, White 1 here seems best. It threatens to cut at 2 so Black has to answer at 2 himself. Despite the connection Black is short of liberties and must submit at 4 and 6. White keeps sente again.
Finally there are three one-point plays left. All are one-sided sente but 3 is the smallest so White will get two of them as long as she starts with 1 or 4.
It looks like White has 30 points to Black's 27; W +3
The book solution had the order of the two sente sequences in the upper right and left reversed, but the result is the same as here.