Can I repair/replace the locks myself?

I have a 96 Ford Mustang. Everything is manual, no automatic controls whatsoever. My trunk lock and passenger door lock don't work with the key. I've tried WD-40 and other sprays to no avail. I think I need to replace them. I don't have access to power tools or car-specific tools. Can I do this repair at home (no prior knowledge) or would this be a job for a body shop mechanic?

The hard part here would be to find a set of lock cylinders that all work off the same key. I'd go talk to a local locksmith and see what he can do to resolve your problem.

Mechanic.