Linq Query using Joins, GroupBy

Question

//Classes
Class Employee
{ EmployeeID,Name,Designation,DateOfJoin }

Class SalaryDetails
{ EmployeeID, HRA,DA,Basic,NetSalary }

        and then i added Collections of data's using List<Employee> and List<SalaryDetails>

How to find 3rd highest netsalary using LINQ query ...

I want result is ID,Name,Designation,Basic,NetSalary. So here, I want use join, groupby

How can get it ?