I have a jetta but mileage is still low so not change pads yet

I don't see why it'll be harder. I changed brake pads on other euro cars, specifically MBs, I didn't feel any harder. It may be a little different, but foundamental is the same.

需注意的事项？
(1) Don't take it as granted that the pad surface is flat, grind it on cement ground to make it flat;

(2) Before change, buy a can of "brake cleaner" ($2.5/can). After the brake pads are changed, use it to clean up the roter surfaces. otherwise, it might squeak.

(3) After tires being put back, don't drive the car right away. Start engine, press the brake pedal many times in small distance (about 1/3 of normal distance) until the pedal is firm. Full length pressing could damage master cylinder.

These are what I can think of now...