FabFilter

Hey there, I've got mastering bunlde, how can I use q2 from someone else project?

You should be able to download is from here: www.fabfilter.com/support/downloads

Your account automatically offers you a license key for earlier versions of plug-ins that you own. First log into your account: www.fabfilter.com/myaccount

Click 'View license key' next to your most recent order for a plug-in, e.g. Pro-Q 3. Then, click on 'View license keys for earlier versions' in the top-right corner of the page. The license keys for earlier versions will now be displayed.

As Selcuk said you can download all earlier plug-in versions here:
www.fabfilter.com/support/downloads