I did my oil change too at 4k and the job was simple... I used Mobile 1 with Mobile 1 filter. The Mobile 1 filter looks identical to the stock, the Pure One looks a little bigger then stock.
There is no way the filter mag will come off! You would have to slide it off for it to come off. As for tools, I used the Race Ramp and I love it!!!! Did you not use a washer on your drain plug?
As for the cover, I just unscrewed the for screws and used a bungee cord to hold the flap back. I connected the hole in the flap to the hole near the wheel well. There is no need to take the whole cover off...
There is a big difference with new oil in my Z... I think the Z loves to be driven now..