Perform Ritual Bath (Ghusl)

Ghusl or ritual bath, according to the rules of fiqh, can be performed in the following way:

1.Once you are ready to perform ghusl, affirm the intention to do so in your mind; this is important since you are doing ghusl in order to make yourself eligible for worship; after which you should do the following:

2.Wash your private parts thoroughly with water; you may use soap and something to scrub your body;

3.Perform wudhu as you would for salah except for the fact you need not wash your feet; which you can do later;

4.Pour water over you head and wash your head; you may use shampoo if you wish;

5.Wash the whole body, starting with your right side, followed by left.

The perfect method of ghusl is to wash the entire body a minimum of three times. However, doing it once thoroughly is sufficient to make you eligible for salah.

After having performed ghusl in the above manner, you need not perform wudhu again, since it is already included in your ghusl with the niyyah.

Reference: Islam.ca