First you need to install
the "UPD. 12.12.12" and then the "UPD 2013.01.02".
In both cases, you need to unpack the archives into the root of the "internal storage" (you must not create any subdirectory there) and then click on the "update.oar".
Note: both updates are for the "NEW / BETA" Pdf Reader (you need to turn it on using "Settings" -> "Preferred Applications" -> "try new Pdf Reader (beta)").