/3/ - 3DCG

ALT + P = Clear Parent (you need to clear the parenting for everything before you move on.

or you can simply delete all the parenting by going to object data and deleting all of the bone groups

to parent anew just click Ctrl + P parent armature, you can use automatic weights if you don't know how to weight paint

btw if its a simple mechanical motion then you don't need bones in the first place, just parent all the object you want into one base parent and they will share rotation.

in this example i simply click all the children (holding shift to select multiple objects, and then the base at the end. after that click control + P parent object).
same thing can be done with armatures, but for those you need weights