I managed to integrate the library. The new file gets downloaded and old one replaced but after relaunch if I click on 'Update' an error gets thrown.
I will try to explain my code - 
I have the following code in a forms constructor
            UpdateManager updManager = UpdateManager.Instance;
            updManager.UpdateSource = new SimpleWebSource(URL);
            updManager.Config.TempFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "Controller_main\\Updates");
            updManager.ReinstateIfRestarted();
And on 'Update' button click -
            CheckForUpdates();
FormClosed - 
            
            if (UpdateManager.Instance.State != UpdateManager.UpdateProcessState.Checked) return;
            UpdateManager.Instance.CleanUp();     
ERROR
   System.TimeoutException: The operation has timed out.
   at System.IO.Pipes.NamedPipeClientStream.Connect(Int32 timeout)
   at NAppUpdate.Framework.Utils.NauIpc.ReadDto(String syncProcessName) in C;\NAppUpdate.Framework\Utils\NauIpc.cs:line 91
   at NAppUpdate.Framework.UpdateManager.ReinstateIfRestarted() in E:\NAppUpdate.Framework\UpdateManager.cs:line 497