Thanks for the answers.
First up, I do know how the connectors work. I even have a couple of spares in a box in the garage, and practised with them before going at it on the bike.
What hasn't been mentioned: it is very helpful to disconnect the fuel pump, start the bike, and let it run until it stops before one tries to disconnect the coupling. This relieves the pressure in the fuel lines, making the whole thing much easier. Last time I did it, I got the thing apart first go after doing that.
This time round, the battery was not in the bike, and I was not motivated to go back home and get it out of the cellar and put it in. I thought that after nearly a year of standing around, there wouldn't be much pressure left in the system. In hindsight, I probably should have put the battery back in. There is a German expression that translates as "in hindsight is one always wiser"...
Regarding the tools: the ones I first found are a set, and were on e-bay for about €20.- . I have since found out that KS Tools offers a set that looks almost identical, but *might* be better quality for about €50.- . Still thinking about it, but I'm likely to buy a set, and probably the one from KS.