[Warning Light] Brake warning lights

[Grez]

Hi, hopefully somebody can help.
Had 4 new tyres fitted today and on the way home I got a brake fault warning buzzer and dash light with a stop warning. 
Obviously fitting the tyres has caused this to happen. Any idea why this happened and how do I get rid of the dash warnings?? 

Cheers in advance.

[jj9]

Check your brake fluid level.

Did you have anything done to the brakes when having the tyres fitted?

.

[Grez]

Just the tyres. Wondered if they’d knocked a sensor or something. Quite worrying when it’s beeping telling me to stop but I knew it was fine.

[jj9]

Check you have no brake fluid leaks at each wheel.

Is the fluid level ok, somewhere between the MIN & MAX?

.

[Sol]

Have they disconnected or broken a pad wear indicator wire that's now grounding out and putting the brake wear warning on.