First your Account ID (AID) is needed.
If you know your AID:
Enter it in the text field below and press "Validate AID".
If you don't know your AID:
If you don't, do the following:
Go to this PSN Login
Login with the PSN account you also use on your Vita
When you see "redirect", copy the URL from the address bar
Paste the URL into the text field below and press "Validate AID"
Select the Homebrew apps you'd like to get:
Generally for hacking you only need:
Everything is ready, you can now click the "Get Homebrews" button get the archive (.zip) file with the apps you selected.
Put all folders from the archive (.zip) file into the folder you've set in QCMA for Backups with you AID.
By default that should be:
After that either restart QCMA or right-click on the small Vita icon in your Taskbar (or left-click on it on non-Windows OSs) and select "Refresh Database".