my rule these days with my car, everything excluding brakes, and internal engine work.
Buy the mod, attempt DIY over 2 weekends, if still nowhere.. put it back to how it was, and then get it done professionally.
This way, i dont break the most important things.(engine, or stuff up my breaks which i NEED to work)
i give it a shot, if i cant do it.. well then i sit at the shop and watch, normally they dont mind
so then I can see where I was going wrong, or why it wouldnt work for me.. so 1) its a cheaper if i can successfully DIY, 2)I give it a shot anyway, 3) I learn more about my cars, so in future i save more money.