Updating from previous version of jv16 PowerTools 2005:
1) Download the updated version: http://www.macecraft.com/downloads/jv16pt_setup.exe
2) Install it over the top of the old installation. There's absolutely no need to uninstall first, this is one of the PT2005's design goals. If you don't uninstall, there's no risk of losing any of your settings, backups or your (possible) license file.
Upgrading from jv16 PowerTools 1.4.1 or earlier:
1) Uninstall the current version of jv16 PowerTools, or simply delete its folder.
2) Download the updated version from: http://www.macecraft.com/downloads/jv16pt_setup.exe
3) Install the new version.
Remember that a license of jv16 PowerTools 1.4.1 doesn't work with the PT2005. For the discounted prices of old cusomers, please see: http://www.macecraft.com/news/76/