Vijay,
It seems u r talking about ULIP policy.
Like other plans for ULIP policies also you need to surrender the policy bond to the insurer in original and ask them to redeem the same in full/partially.
But u need to verify few points:
1. Lock in period under the policy?
2. Whether partial withdrawal is permitted during lock in period?
3. what are the surrender or redemption charges.
4. what is the present units and fund value accumulated vide your policy/ account?
The insurer may ask for your bank particulars and surrender request .
warm regards
Shyam Sunder