you can edit word, excel, and powerpoint files with the docs-to-go apps that should have been included on your berry. and pdf files can be viewed as well. so, i'm not sure what you're looking for.
as for "cracking" an app, just bone up and pay for it if you have to have it.
DocsToGo already should come on your BB (OS 4.5+). If not, you should be able to install it for free. That will give you the ability to view and edit Word and Excel files. The e-mail app already has the ability to view PDF attachments.