Hi,
That is not possible. The SFP ports on that model are 1Gig and cannot be upgraded to 10Gig.
You need a different switch that supports 10Gig.
Have a look at the 2960x data sheet:
http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-2960-x-series-switches/data_sheet_c78-728232.html
HTH