Out with the old, in with the new...And Improved! Getting the old one out was a chore, but the PB Blaster helped. I was really careful with the cat studs so as to not break them off.
I still haven't tightened everything up or started the car with the new exhaust yet, but just getting everything in place and test fit was such a win that I just had to share. I was even able to salvage the downstream O2 sensor!
With no experience in the DSM world and having never bought an aftermarket exhaust, I feel like I got kinda lucky in purchasing such a nice quality item. Not that I didn't do my homework, I did a fair bit of looking around before buying this SR-S system off Amazon.