Tamper with

tamper with sth (phrasal verb)
to touch or make changes to something which you should not, usually without enough knowledge of how it works or when you are trying to damage it

Example:

It was not easy to find a suitable site that was safe, secure and not tampered with by animals and birds.

The retail director of ExxonMobil ruled out the possibility the station contractor had tampered with the dispenser to make money.