Need to know how to go about cutting up a semi-trailer frame

Ok guys and gals, here’s the scoop

Got an email for a job to remove what is essentially the remaining frame from a semi-trailer that was left on a property and deteriorated. It can’t be towed or anything so we’re thinking it would have to be cut up. What’s the best tool to use? I’m thinking of pitching the idea of buying a cutting torch but that’s a decent chunk for an up-front cost. Thoughts?

I’m thinking Patriot’s going to be my man on this one but anyone else who has dealt with these in the past, I would very much welcome their input.

PICTURES!