How do I install plugins?

I know there is a lot of answers, but it still won't work! Every time I try it won't work. Im trying to download this one.

https://www.scirra.com/forum/plugin-3d-starfield_t150815

It just won't work.

There's a sticky post in the completed addons section of the forum that tells how to install them, that's probably useful to look at.

Basically:

If the plugin/ behavior has a .c2addon you can drag and drop it into the editor itself.

Otherwise you need to go to the construct 2 install folder, find the folders of plugins or behaviors and copy the plugin/behavior in depending on what it is.

The guide explains it better, and maybe you can compare what you've tried to what it says and see what was wrong to make it not work.