This is my Test Method:

@isTest
private class ContractMasterControllerTestClass2{
    static testMethod void contractMastermethod(){
 
      ApexPages.currentPage().getParameters().put('id', '800O00000000Kp4');  
        ContractMasterController  ct = new ContractMasterController();
       
        List<ContractMaster__c> c = ct.getContractMasterDet();
        List<ContractMaster__c> t = ct.getContractMasterreports();               
       
        ContractMaster__c conmaster = [SELECT Specification_on_dry_basis__c,Fines__c,Lumps__c,UltraFines__c from
                                        ContractMaster__c where Name=:'000153'];

       /*List<ContractMaster__c> cupdate=new List<ContractMaster__c>();
       List<ContractMaster__c> cinsert=new List<ContractMaster__c>();

update cupdate;
insert cinsert;*/
        // Retrieve account
        ct.coninsert= [SELECT Status, Seller__c,
        Buyer__c,
        Account.Name,
        ContractNo__c,
        Commodity__c,
        FinesQtyperyear__c,
        LumpsQtyperyear__c,
        UltraFinesQtyPerYear__c,
        AdditionalQtyifany__c,
        EndDate,
        ContractTerm,
        StartDate,Fines__c,Lumps__c,UltraFines__c
        FROM Contract WHERE Id =:'800O00000000Kp4IAE'];
       
        Date dat = Date.today();
       
        Contract newcon = new Contract();
        newcon.AccountID='001O0000001nmuG';
        newcon.Name='TCS';
        newcon.Status='Draft';
        newcon.StartDate=dat;
        newcon.ContractTerm=15;
        insert newcon;  
          // ct.setconinsert(newcon);
  
PageReference pref1 = ct.MyUpdate(); 
        update newcon;
        delete  newcon;
 
    PageReference pref2 = ct.MyEdit();   
    PageReference pref3 = ct.Cancel();      
    PageReference pref4=ct.MYSave();
       System.debug(pref4);
      
    }

I got the Following Error:

System.DmlException: Insert failed. First exception on row 0 with id 800O00000000Kp4IAE; first error: INVALID_FIELD_FOR_INSERT_UPDATE, cannot specify Id in an insert call: [Id]

Could you Please Provide me the solution for this.
   
}
 
}