My grandpa disabled my car and now he can't get up to fix it from health issues

What is your question?

I have a 1995 Ford taurus and I need to know all the ways to disable this car (that's are easy) that my grandfather would have done. I'm trying to because he's not able to get out of bed to do it for a while but when I ask him what he did to disable it so I can fix it, he says he's gotta keep that a secret incase he needs to do it agaon