2000 Jeep Wrangler Removing the

I am replacing the heater core. To remove the entire heating assembly (on the passenger side of the firewall), I need two disconnect two air conditioning line connections (on the engine side of the firewall) that come from teh evaporator. I am not sure how to disconnect this particular type of connection. A Jeep dealer person described it as a 'quick connect' connection. I bought a set of tools at an auto parts dealer that should have included a tool that could be used to force the disconnection. But it is unclear to me that these tools, composed of little plastic rings are really the correct thing to use. At any rate, I could not get the tool to work. I need specific instructions how to perform this disconnect. Again, a nut and threads ARE NOT involved in the connection. It appears to be two flanged ends joned by an outer aluminum ring, something I have never seen before. Thanks.