How does one do ghusl-e-irtimasi?

Ayatollah Sayed Ali Khaminei (r.a) says as follows:

The obligations of the ghusl of janaabah are as follows:

a- Making intention, i.e. to intend to do the ghusl of janaabah for the sake of nearness to Allah, the Exalted.

b- Washing the head and neck whether to start with the head or neck. What is significant is to wash them with the intention of doing ghusl.

c- Washing the entire right body side from the shoulder until the toes and sole of the foot. For being sure of full washing, some of the adjacent areas of the left side and one half of the neck are included (for caution).

d- Washing the left body side in the same way explained above along with including the adjacent areas of the right side for caution. It is also advisable that the middle parts like the navel and private area are washed when performing phases c and d.

You should make sure that the parts you want to give ghusl to should be pure. If they are najis, you have to purify them first and then give them ghusl. Therefore, if genital is najis, it should be washed and cleaned before washing the right body side, and then wash it for ghusl.

4) You can make ghusl while your body is wet.