I'm using Winrar and all the files you linked appear correctly when downloaded, probably your download got corrupted or you attempted to open it before the download finished 100%. Retry downloading the corrupted archive. The first update, the firmware for your device you don't have to unpack, just copy it to the micro sd card, your ereader will do the rest. The pdf reader update needs to be unpacked and copied to the root directory of your device. Unpack in a folder on your PC (the "extract to" command). There should be two files: onyx_pdf_reader and update.oar. Then copy/paste to the reader's main memory via the usb cable. Disconnect the ereader from the pc! Perform the update by clicking on the update.oar file (by using your ereader buttons) delete the two files.
EDITED post, please check the final version, I apologize for the confusion
Last edited by yayo; 02-08-2013 at 08:06 AM.