How can I correct the heading for this navigation problem?
The correct answer is 12 degrees.  The problem is as follows:



To determine wind correction use an E6-b or similar.

Set distance off course over distance already flown.  In this case, $\frac{4.5}{45}$. The degrees to eliminate wind drift will be under the rate arrow, in this case: 6.

Then, determine how much additional correction is needed to rejoin.  In this case, $\frac{4.5}{45}$ again.  You must add 6 more degrees to the first 6 to rejoin.

The total (therefore the answer) is 12.