How to Check In Sharepoint Document without Adding Required fields using Web Services ?

Question

I am trying to Update a document programatically where some of required fields are missing.(and we need to checkin document before updating) In order to checkIn document all required fields should be added.

But problem here is that to add those required field i have to again Update the Document :(

So is there any way:

1. To CheckIn Document witout adding required field. or
2. To add those required field without using (UpdateList anf UpdateListItem methods of List.asmx)