Contested divorce

appears that your friend is already in the battle feild. If he is willing to divorce his wife let him file the divorce case in the court,there is no bar.Since his wife is not willing to divorce him means the divorce would take much of time energy and money. It is better to do some amicable settlement, however the relationship is already starined so better to perusade and make the wife to agree on mutually consented divorce. Needs to much of hectic work.