I have an int'l to int'l connection at PEK but may have to recheck my baggage there. How do I do it?

I will be flying from Siberia (IKT) to Europe (HEL) with a connection at PEK. The flights are on separate tickets, so I may not be able to check my bags through from ITK to HEL and will have to pick them up and recheck them at PEK. What is the procedure? How long will it take to do this? (I have 6 hours between flights.)