Slackware is using .tgz packed packages wich you can install/uninstall/upgrade with the following installpkg/removepkg/upgradepkg.
1. installpkg is like: installpkg <package.tgz> or installpkg * wich installs all the .tgz packages in the current dir you are in at the moment.
2. removepkg is like installpkg on you use removepkg command to remove packages.
3. upgradepkg just like the other 2
Hope it helps, and it is the answer to your question ( it will be if I understood your question well :P ). Cheers.