Read this user tip, the documents must be converted in 10.6.8 or earlier, except for Appleworks 6.2.9 word processing and spreadsheet documents.
If you don't have a Mac with Mac OS X 10.6.8 or earlier possible, you can install Parallels and Mac OS X 10.6 Server on many Macs that don't support Snow Leopard client. There are numerous entries for that in the forum. If that is too cost prohibitive, see my used or refurbished Mac page*
Or consider having a http://www.apple.com/usergroups/ member with an older Mac help you.
Another option: Run Appleworks 6 in Snow Leopard (with Rosetta) installed into Parallels in Lion:
[click on image to enlarge]
Full Snow Leopard installation instructions here: