Folding in tools locked in their 'out' position on a multi-tool garden handset?

Question:It's a bit like a Swiss pen knife - the tools get clicked/locked into their out position while in use, but I can't work out how to unlock them to fold them back in to the handle. Any ideas? I'm sure it's very simple but I can't work it out!!

Answers:
There should be a metal collar, ring type thingy which needs sliding back or twisting if it is anything like my set. Good luck.