how to edit expired contract in crm 2011

There is an unsupported method to do this you can do in database table ..contractbasetable and update the statecode and status code column to make it draft again..

(this is unsupported way also test the SQL Update on Dev/Test Environment before running on actual Live Environment)

 
update ContractBase
set StateCode = 0,
StatusCode = 1
where
ContractId = <<YOUR Contract ID>>

Run the above query and when you open your record in crm 2011 it will be draft update the contract and save it.

Thanks and regards