Caster is adjusted by turning the cam bolts on the lower control arms.
You can't. Have the job done at a wheel alignment shop.
lowering coils or coilovers. camber/caster balljoints on the front. strut cambolts on the rear.
technicaly speaking there is no need for a caster angle on your rear wheels, this angle is set in to the front wheels to aid self centering of the steering, like on a shopping trolley wheel. unless your rear wheels are steered or damaged in some way there is not usually a way to adjust this angle.
Adjust rear of car then front of car. Adjust in this order: Caster, Camber, Toe.
the bolts in the upper control arm have cams on them to adjust the camber and caster.
check front caster/camber and toe , and then possibly adjust to within specs.
Camber is done by adjusting the lower control arm bolt. Caster isn't really adjustable. you can buy a kit from toplineparts.com that will give you more adjustment.
Adding or removing the shims on the upper control arm can adjust camber and caster.
That depends on weather you need to adjust the camber, caster, or toe... The toe is the easiest to adjust that is done by screwing the tie rod ends in or out depending on what you need.. Camber and caster is much more difficult but that is done by adding shims to the upper control arm.. But I would recommend taking your car to the shop for an alignment that should cost between $50 to $100 to make sure all is done right..
if you have the right equipment camber and caster is easy to adjust, but can be a pain to get it just right.. especially if you are doing it yourself.. (use wrenches to adjust, but location in degrees can be difficult with the small alignment tools) it will take alot of time if you do it yourself, and I would recommend taking it to a shop, and just letting them do it. front should have 2 bolts to loosen, one is lock, the other is adjustment. unloosen the lock, adjust to the desired location, then tighten the lock. the rear to my knowledge is only adjustable camber, but not caster, or caster, but not camber, or vice versa.. they make the cars to easily swap the parts out, but not to adjust. its just the stupid throw away society we live in.
Alignment term. There is camber, caster and toe. Toe is wheels in or out towards each other. Camber/caster is just in or out top and bottom and is adjusted with shims. Any alignment shop can cheaply check and adjust all three.