I arrive on a Delta flight from the US to Beijing Capital Airport at 3:15PM

And have a Departure on a China Eastern flight to Kunming at 6:35PM. It looks like both arrival and departure are in Terminal 2. I was told I'd need to pick up my bags and recheck in at China Eastern after Passport Control. Is 3 hours enough time? And can anyone tell me what the quickest route from the Luggage area to China Eastern Departure is? Is it just a matter of going up an escalator or two?