I believe they are all garter-spring type connectors except for the two lines going on the compressor which is held by a single bolt and sealed with o-rings...
You can buy tools to disconnect the connectors at auto-zone, advanced, etc. They snap around the hose and slide into the connector and open the spring up so you can separate the thing at the joint. They are sometimes stiff as there are usually 2 o-rings on the male part of the connector and they can get sticky after being undisturbed for a few years.