Enter at rear
There's a reddit post from a security tester showing how to beat entry locks.
1. Find door outside which smokers congregate.
2. Create suitable incident to get somebody outside (like setting off a car alarm).
3. Pretending to be talking animatedly on cell phone, wait for door to open and dash inside.
After that, it's "adopt local color, make like a maint. guy etc." Infallible.