Brake calipers stick when they get old. You need to replace it and the other side While you're at it.
two bolts in the steering knuckle and the brake line are all that attach to the brake caliper
you have to remove the caliper to access the brake pads
caliper froze, brake line collapse, or wheel bearing out.
Torx #45
Hub Knuckle
I believe that caliper is held with 10mm bolts. Remove caliper, then caliper mounting frame, then rotor will come off.
3/8 inch
If memory serves, 18mm. That would be the bracket bolt. The caliper bolt has a 9mm thread.
Sticky caliper.
Remove brake caliper then caliper mounting frame, held to knuckle by 2 bolts lower down.
If the front brake caliper is sticking, the disc may be uneven. Brakes that are left to scrape on the disc for a long time before they are changed will damage the disc enough to cause sticking or slipping.
Unless the caliper is broken, you can just replace the brake pads.