How do I install (apply) micropatches when they're downloaded?

Micropatches get applied automatically by 0patch Agent - you don't have to do anything.

In contrast to traditional patches/updates that you download and apply manually, 0patch micropatches get downloaded and applied automatically*. They get applied - in memory - to processes running on your computer, so while a traditional patch is applied only once to a file, a micropatch can be applied hundreds of times to different running processes.

* Enterprise users can set a different policy preventing micropatches from getting applied automatically.