Instructions to download Revit symbols from PartnerNet:
1. Download product symbol from Partnernet
2. Open the zip and save the .rfa and .txt files in a folder
3. Open a project
4. Go to Architecture tab
5. Click on Component
6. Click Load Family
7. Select the .rfa file
8. Select all the types you are interested in loading into the project.
9. Click ok and if a pop-up message comes up then click yes.