Once you have paid the stamp duty and registered your sale deed with the sub-registrar, you should apply for Index II.
Then you approach the local revenue officer/Talathi and apply for a change in name due to the transfer as per the sale deed. This requires a non-judicial stamp to be affixed to the application format available with the talathi and also the original certified copy of the Index II.
The talathi will get the name changed in the saat-baara as per procedure after which you can apply for a new saat-baara showing your name.
This process takes a few weeks/months.
You may consult the local talathi or the persons from the sub-registrr/revenue office to help you. Alternately, please approach a local lawyer who will get this done for you.