1. Both of them married in India as per Hindu rites if not as per Hindu Marriage or special Marriage Act,
2. Let your friend collect evidence of her husband's second marriage without obtaining decree of divorce from his wife,
3. After that your friend should file a police complaint against him alleging bigamy which is a punishable offence,
4. Her husband will now be in trouble to save her from police arrest in India,
5. After that your friend should file a divorce suit o the ground of cruelty since bigamy is extreme form of cruelty,
6. She will get ex-parte decree of divorce if he fails to attend the hearing,
7. If he comes to India to contest the divorce suit, he will be arrested by police for committing bigamy which he will tray to avoid,
8. At this juncture he may agree for signing the mutual consent divorce petition to be filed in India which will be disposed of within 6 & 1/2 months from the date of its filing.