Expired F&O contracts charts

I want to study 1minute span charts of weekly options of Nifty and BankNifty contracts that have expired, especially their movement on their expiry day. But Kite removes an options charts after they’ve expired. So how can I do it?

You can take data,save it every week and study.

Can you explain it in detail?
Especially what can be done to extract past data? Can Zerodha supply it or I’ll have to buy from some other data Vendor?
Which one will be the best?

You can use Kite Connect APIs to store the chart data and use it for backtesting.
Check out kite.trade for more details