This is how the prison looks like
Go to the yard and find the hammer
Pick up the hammer
Go to the prison cell
Go to the toilet and equip the hammer
Click on the toilet until it breaks into pieces
Crawl into the hole where the toilet used to be
Drop down into the sewers below
Find the ladder at the end of the sewer and climb it
Find the ladder at the prison wall. Watch out for guards!
Climb up the ladder and over the wall
Congratulations! You have escaped Prison Life!