Here are some steps you can follow to test your body fat:

1. **Skinfold calipers**: This method involves using calipers to measure the thickness of skinfolds at different points on your body. The measurements are then used to calculate your body fat percentage. You can find detailed instructions on how to use calipers [here](https://www.wikihow.com/Use-Body-Fat-Calipers).

2. **Bioelectrical impedance analysis (BIA)**: This method involves using a device that sends a small electrical current through your body to measure the resistance of different tissues. The measurements are then used to calculate your body fat percentage. You can find detailed instructions on how to use BIA [here](https://www.healthline.com/health/how-to-measure-body-fat).

3. **Hydrostatic weighing**: This method involves weighing you both in and out of water and calculating the difference between the two weights. You can find detailed instructions on how to use hydrostatic weighing [here](https://www.bodybuilding.com/fun/becker11.htm).

4. **Dual-energy X-ray absorptiometry (DXA)**: This method involves using a scanner that emits two different types of low-dose X-rays to measure the amount of bone, fat, and muscle in your body. You can find detailed instructions on how to use DXA [here](https://www.bodybuilding.com/content/how-to-measure-your-body-fat.html).