How to import existing stored procedure in Entity Framework code-first from entity data wizard?

You don't need to import the procedures.

Use of exisitng store procedures(InsertStudent,UpdateStudent) are shown in code sample. Just need to override OnModelCreating method and map store procedures with entities.

Kindly refer to this page http://www.entityframeworktutorial.net/EntityFramework6/code-first-insert-update-delete-stored-procedure-mapping.aspx for detailed information.

public class SchoolContext: DbContext 
{
   protected override void OnModelCreating(DbModelBuilder modelBuilder)
   {

     modelBuilder.Entity<Student>()
        .MapToStoredProcedures(p => p.Insert(sp => sp.HasName("InsertStudent").Parameter(pm => pm.StudentName, "name").Result(rs => rs.StudentId, "Id"))
            .Update(sp => sp.HasName("UpdateStudent").Parameter(pm => pm.StudentName, "name"))
            .Delete(sp => sp.HasName("DeleteStudent").Parameter(pm => pm.StudentId, "Id"))
        );
   }
}