MARK, I don't mean any disrespect by this but if these are the sorts of questions you are asking, then maybe you need to consider having the service done by others. The intercooler is easy enough to remove, but there are some issues that you need to be aware of, such as not losing a metal object down the plumbing and having it shred your turbo, or similar disaster. And then getting a leak free connection when you do it all up again. You need to be surgically clean and tidy. The plugs are down deep tubes that accumulate grit and you need to take care that none gets into the plug threads or cylinder. And so on. The oil filter is accessible after removing the bottom shroud - 6 x 10mm bolts.
I'm entirely competent mechanically but have no problem with letting Mazda do the work - I pay them to do something they are qualified to do, plus they have the diagnostic computer, while people pay me to do what I'm qualified to do. It saves me time, which is money. And my car gets a wash and vacuum too. Unless your dealer is particularly bad, in which case Australia Mazda needs to know about them, then going elsewhere can be false economy in my view.
CP_e Standback & PNP; CP_e 3" SS Downpipe; Corksport FMIC with Top-mount K&N filter & OEM Ram CAI; Turbosmart BOV; Dashhawk; Prosport Boost Guage; JBR solid shift bushes; DBA 4000 Wiper-Slot front rotors; Hawk Ferro-Carbon HPS Street front brake pads (@ 69,000km); Sumitomo HTRZIII's in 225/45 x 18