Try this:

1) Open Poser, and right-click on the Downloads folder in the library

2) Choose Show in Explorer (or Show in Finder on the mac)

3) in Explorer or Finder, choose the Downloads > runtime > libraries > Pose folder

4) Add a folder name that is descriptive of the poses you are using. (example: My Poses)

5) Copy all the PZ2 files and PNG thumbnails into that folder. Now you should see them in the Downloads folder in the library and you can just double-click the poses to apply them to your character. Generally, you should apply poses to the character that they were made for (example: La Femme poses to La Femme, Victoria 4 poses to Victoria 4, etc)