After it's installed, the plug-in should be available through the usual Effects menu, but you will have to make sure that the correct version of Photoshop is installed on your computer. According to the Readme file, the plug-in works only on the following versions:
WINDOWS SUPPORTED HOST APPLICATIONS
- Adobe Photoshop 5.5, 6.0, 7.01, CS, CS2 and CS3
- Adobe Photoshop Elements 4.0 and 5.0
- Adobe PhotoDeluxe Home Edition 4.0
- Adobe Photoshop LE 5.0
- JASC Paint Shop Pro 7.04, 8.1 and 9.01.1
- Corel Paint Shop Pro X and XI
- (may also work with other Photoshop plug-in compatible applications)
While you are installing it, make sure the Photoshop application is closed. Restart it and then you will have the possibility to access the plug-in menu.