It does not cost much, is professional and can prevent major bleeding head injuries. Then of course we are talking about tools and specifically about the spring clip.
Every year, people come to general practitioner posts and first aid departments because they have worked with improvised tools when dismantling - mostly - struts. Because it seems so clear: to mount the case, the tension of the coil springs must be released. And there are a lot of solutions for that on a quiet Sunday afternoon.
Unfortunately, most of these solutions do not take into account the not insignificant forces that occur during such an intervention.
That is why, over time, legion of crafty tools have been thrown away, broken, or whatever. We know from our own experience that with an improvised spring clip of 12 mm Bruijnzeel Hechthout (which is top quality) and a few pieces of M10 threaded rod, the threaded ends are in any case not the weak point. That learning moment ended with six stitches and the purchase of a set of real spring clips. You can find them at our advertisers or at your local car parts specialist such as the Brezan.
Lots of key fun!
But stay careful.