These documents are in the form of (PCL) print files (.prt) that work with HP LaserJet (series 3 and higher) and compatible printers.
You must download the .prt files (ASCII mode is fine), and then send them to your compatible printer via theoperating system without passing them through any other program or filter. In DOS, the command
type filename.prt > prn
will work, where filename.prt is one of these print files. You cannot view print files with a Web browser, and I know of no useful way to import them into any word processor.
If the above does not work, you need to contact the sender and find out how you may view these files. There are many means, it just depends on the specific manner in which they were created.