Husband engaged with an other lady and got married

One of my female cousin who is orphan as well has 5 daughters ( approx 11 yrs of marriage) , her husband is stationed temp at Dubai and is in Dubai police, owned private business at Dubai as a side job. He seldom visit Pakistan to see her wife and kids in a joint family system. Very sad at his part that he engaged with an other lady in family and got married latter despite lot much hindrance and quarrel with the better half. The resistance could not pay much dividend and they both united without the consent of 1st wife. Not he is making lot much excuses and every day is hell due to yelling and all the time unrest at home. Now he want to divorce her and finding the way out. He may flew back to Dubai with his second wife with in a month. Kindly suggest the legal course of action to deal with the matter.
Regards