Acron plugin deleted

I mistakenly deleted acron plugin. I want reinstall acron plugin. please help me.

You should check what OJS version you use. Then download that version from the PKP site and upload the acron plugin folder to your installation.

After that it probably works already because Acron is already registered, but you can of course run php tools/upgrade.php upgrade.

How can run php tools/upgrade.php upgrade?

You run that from the command. But probably you do not need to. Did you upload a new acron plugin to the generic folder already?

I upload in acron plugin to the generic folder . but i dont know run.

Depending how you deleted it, it could work already now. To run the command you need shell access, I do not know what kind of system you are working with, so it is hard to give better instructions. In OJS3 I think someone mentioned that it is enough that you go to settings => website => plugins and check the enabled box. Can you see Acron in that listing now and is it enabled?