I'm about to do mine too. I have the core, need to find where I put the O rings, but what clips are you talking about?? (I might need those too).

You should be able to remove both hoses that go to the heater core and simply blow into one and catch the fluid coming out of the other. No need for a compressor (I have one and I will still do it this way). You don't need high pressure to get the fluid out...BTW there will be some that will drip in, so having plenty of rags is a good idea.