How do I unpack this?

So I downloaded the Unleashed version of Titan Attacks, but cant figure out how to unpack it.
It comes in a .rar which contains several zips. These are named unl-tiaa.zip, unl-tiab.zip, unl-tiac.zip, etc, etc, till unl-tiah.zip. Inside these zips is another .rar, which in turn contains the installer. Why they made it this tedious is beyond me, but I’m used to unpacking from the first part (in this case the unl-tiaa.zip and then it would unpack properly).
I’ve tried it with both WinRAR and 7-Zip, both giving me only the contents of the .zip I’m unpacking (it doesn’t combine the content of the other .zip).
Sorry if my explanation is a bit vague.
Answer #1
You should extract ALL zips, Each is a separate archive! just select all of em>right click>extract here
When done, Extract from the .rar or part1.rar file.
Answer #2
That did the trick, cheers!