You cannot spot tone. All /most women have trouble with these areas where estrogenic fat is stored: back of the arms, lower back, inner thigh, lower abs.
What I can suggest to you is to lessen up your cardio and concentrate more on weight training for burning fat and strengthening muscle.
I will tell you how I currently train:
Monday: chest and triceps
Tuesday: back and biceps
Wednesday: legs
Thursday: shoulders
Friday: abs and maybe calves
Saturday and Sunday: off from weight training, these are cardio days.
There are plenty of exercises to do for each of these body parts and plenty of resources. I suggest that you do a little bit of research on weight training exercises as well.
How is your diet? Diet is VERY important!