I used to brew beer on a regular basis and used kegs almost exclusively.
Iâ??ll try to explain; first you need to put a nail into the ball valve to wedge it open. This is to prevent pressure from building up inside the keg. Next there is a snap ring on the top of the stem assembly; this snap ring is tapered at the ends. Use a small flathead screw driver and pair of needle nose pliers to pry the snap ring out. I found it easiest to pry the ring with the screwdriver at the taper in the notch of the keg flange inward to the ball and then grab it with the pliers. After the snap ring is removed, the stem rotates 90 degrees and comes out in one piece.
BTW, after itâ??s removed find a rubber pipe cap with worm clamp to hold in the sand and keep water out.
It tricky at first and took me 30 min or so the first time but after you get used to it you can do it in 5 min.
Remember to keep the nail in the ball less you wish to have the stem shoot through you head.
Sorry, no picts. Right now as I am at work.
Sorry, just re-read an noticed the European Sankey. Check this link out,
I would trade the keg out for an snap ring style before doing this.