If you have six months to lose weight then you could look to lose up to 4lb depending on how much weight you could safely lose. Over this long time period you need to ensure that you do not cut out any nutrients of food groups your body requires. Through not eating a balanced diet your health will suffer and your body could crave the foods you have cut out.
A spcial occassion or goal is always good to focus on. If you do not have an occassion in mind set a date by which you want to lose the weight and organise a big night out, celebration or some special treat as a reward.
To lose weight over six months you should limit your carbohydrate intake to breakfast and lunch and introduce a small protein based snack late afternoon to prevent craving and snacking.
In addition to this you should ensure you are drinking enough water (2 litres a day) and take regular exercise three times a week. The exercise can be gentle ranging from anything from walking, swimming, jogging, or cycling to exercise classes. Ensure that you pick exercise or activities you enjoy or you will not keep the exercising up. Gradually you will form a routine and the exercise will become second nature to you.