Yaroslav--Assuming you are in the USA the procedure is more or less:
* Carefully package the body along with a Nikon Service Request form (you can print it out from NikonUSA website).
* Send it in along with a copy of the sales receipt, keeping a copy of all documents for your self of course.
* Send it insured & trackable (I use Fedex Express Saver, for example) to one of their two locations (NY & CA, addresses on their site)
* You should get an email & postal mail confirmation of receipt & cost/warranty coverage once they get a chance to examine the camera (can be 3-10 days). If not you should of course start calling them via phone.
* You can approve the work online (for warranty work this is typically automatic), and also check the status once you have the Service Order # they sent you in the previous step.
* Then hopefully they have the needed parts & can send it back fairly quickly!--David