Don't, you'll be too skinnny. At you're height you don't want to weigh much less than you already doo.
source:
http://www.rush.edu/rumc/page-1108048103230.html
At 5'3", if you lose 30 lbs, you will be way under weight. Depending on your age, your weight is about perfect as it is. Perhaps you only need to tone your muscles. Exercise can help with that, particularly, yoga and walking.