There are two phases of carbo-loading. The depletion stage is where altering the diet soon after high intensity training depletes the Glycogen Stores. The replenishing stage is where glycogen stores are re-synthesised to above 100% to 150% by consuming an increased amount of carbohydrates.

Glycogen depletion- A few days before you begin glycogen packing, reduce your carbohydrate intake to about 55-60% of your total calories. This will prepare your body by depleting existing carbohydrate stores to make room for the excess carbohydrates.
It is recommended that your macro nutrient ratio is 60:20:20. Make sure to consume your full caloric intake to avoid muscle loss. Maintain high intensity training until fatigue during this period to ensure depletion occurs.

Glycogen replenishment- Glycogen packing is usually about 3 to 4 days before an event. Increase your carbohydrates to about 70% of your total calories.
It is recommended that your macro nutrient ratio be about 70:15:15. Another variation of this phase may be 70:20:10, where about 20% of your intake is from fat and 10% is from protein. However to avoid excess weight gain, it is suggested to limit macro nutrient ratio to 15% fat and 15% protein to 70%carbs during the first 24 hours. Reduce training intensity to prevent burning glycogen stores. When carbo-loading, it is important to consume low-glycemic-index foods. This will help to ensure only moderate levels of glucose will be entering the bloodstream over a duration of time. Carbohydrates high on the glycemic index will lead to quick, large amounts of glucose entering the bloodstream causing insulin levels to fluctuate. Maintain a good source of vitamin and mineral supplements.

Carbo-loading frequency- If one carbo-loads too often, performance levels can actually be inhibited and if done over an extended duration carbo-loading can become ineffective. Carbo-loading should be limited to no more than 3 times a year.