Eclipse: How to install a plugin manually?

In one of my production environment, we have download restrictions so we have to download Eclipse plugin jar/zip file externally and then copy back to internal network and do the installation manually. Plugins to install are TestNG, C++ CDT etc.

Would appreciate step-by-step instructions to perform the above task and would this manually installation have the same outcome as if we do it from Eclipse install new software option like for example- automatically creating menu option for TestNG etc.?

You can try this

click Help>Install New Software on the menu bar

1. Download your plugin
2. Open Eclipse
3. From the menu choose: Help / Install New Software...
4. Click the Add button
5. In the Add Repository dialog that appears, click the Archive button next to the Location field
6. Select your plugin file, click OK

You could also just copy plugins to the eclipse/plugins directory, but it's not recommended.