One of my 32 year-old spinners:

My preferred implement - a Thor aluminium/super-plastic No.2, the plastic end a bit mushroomed after 30 years (replacement faces are available) but still plenty of life left in it and no damage at all to the spinners:

Wooden 'spinner spanner' for eared spinners. Gentle on the chrome of the spinner, you may be able to wrench them loose by hand but other than that hitting the arms with a hammer puts it close to bodywork unless you position it vertically and hit the lower arm, which is awkward: (Moss Europe)

Metal 'implement' for eared spinners - likely to mark the chrome and taking up quite a bit of space in the boot: (Moss Europe)

Octagonal nut: (MiniMania)

Metal 'implement' for octagonal nuts also likely to mark the chrome: (BMC Parts)

Heavy-duty version ditto even though they are unlikely to need hammering, again takes up quite a bit of space in the boot: (Moss Europe)