Kashish Verma,
There is nothing called spot reduction.....when it comes to loosing weight it is different from men to that of women....both loose at different places and to an extent it also depends on heridatory factor also, i dnt say completely depends on heridatory factor.
Just walking may not help and the point to keep in mind is the intensity with which one does the walking.
Strength training is so crucial for loosing weight and maintaining it....when i say strength training not necessarily working with the weights....it can also be doing the workout with the BODY WEIGHT itself...especially for loosing the fat in arms one cnt neglect it....!!!!