Go to you start menu on your computer .... My computer ... local disc c ... program files & find Adobe folder which should be near start. Click on Photoshop folder. Now i have two plugins folder. One that if i put my filters into it they don't go into my programme. Click on the folder Plug-ins. Now copy your filters from where you saved them on your computer. If they are in a zip folder unzip. Then paste them into the Plug-ins.
If you have photoshop open you will not see the filters until you exit and open it again.
Intalling Program filters ...
Just basically like installing anything. Double click to start installation. When it says specify folder to install to, browse to your adobe ... photoshop ... plug-ins folder & then proceed with the rest of the set up.