are there DIY instructions anywhere on [how] to R&R the timing belt? I need to do it on my RS.
Yes. Pick up the Haynes Subaru Legacy Repair Manual from your local bookstore or auto parts store. It has just about as much detail as the Subaru manuals, but presented differently.
Remember to take note of where all the notches are on the pulleys, as the factory doesn't always line the marks on the belt with the pulleys (my guess is that the assembly line worker was showing off that he/she didn't need to use those marks when building the engine).