And to add on that good advice ...

I would rotate the wheel through a full rotation or two while applying that tension. So you'll need both front wheels off the ground. Can have the wheel off on the side of the joint you're replacing and have a helper rotate the wheel on the other side. I think the tension, combined with the rotation will allow the C-clip to center itself and compress slightly before the hammer hits.

Yes, this may fit the category of things that are a little extra work to avoid a disaster rather than something that is absolutely needed. But that's what I try to do - avoid disasters first. Such as when I choose this path rather than even touching the axle nut if I can avoid that.

And if you buy new GKN boot kits like I did, they come with new C-clips, a couple of options as I recall, expecting that one of the two will be a good match for what you need.

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2001 X5 3.0i, 203k miles, AT, owned since 2014