How do you make a hole in this roof?

Current code requires us to run a pipe through the roof when we repair a service. I had a customer today who wants us to redo his service, but making a hole in clay tiles is a whole new game versus drilling a whole in plywood and shingles. Here is the roof. I need a 2 1/2" hole put in it. The house was built in 1935 and the customer doesn't have any extra tiles.



Any ideas? Anyone know a roofer who can cut a hole and seal it when we are done with minimal damage?