Do _you_ know what three easy replacements are? If no, how do you know those people are looking to pad their resumes, did you figure that out from your non-SF conversations?
definitely not easy by yourself, but the whole process (change, then alignment etc) shouldn't take a decent mechanic's shop more than a couple of hours. I've changed tires on my nearly 200k mile car several times now, and it's usually a few days for the tires to be delivered (in america the mechanic will just receive it) and a 2h appt to get the work done. I'm shocked your parent comment mentioned waiting a whole day at the mechanics'.
My friend does this at Costco, and it takes longer purely because of appt mismanagement and backup, the work itself is quick.
> This is potentially easier than reliably shooting guns at people.
I suspect the shooting guns robots will be used against populations the owner considers sub-human, and reliability (accuracy in this context) is not a concern as long as it doesn't turn around 180degs.