Ok, I have just replaced by front bearings and disc's and thought that a wrtie up might be helpful to some. It's not overly difficult just a little time consuming.
Firstly, get your tool together:
flat-head screw driver
mallet
22mm spanner
10mm 17mm sockets
pliers
rattle gun or super buff mate
now if you can't get this far, stop now!
grab your 12mm socket and undo the bolt on the bottom of the calliper.
swing the calliper up and slide off and rest somewhere, it is important that you don't let it hang off the brake line!
now grab your 17mm socket and undo the two bolts, top and bottom, on the pad bracket.
it should come off and look like this. at this stage you can replace your pads if need be.
getting the hub off the stub axle. use the screw driver and mallet and gently tap around the cap and work it off.
use the pliers to bend the split pin straight and pull it out.
take the retainer off and remove excess grease.
use the 22mm spanner and loosen the nut. it shouldn't be very tight.
take off the washer...
now carefully take out the outer bearing. (note these are new).
gently work the hub off the axle, it might be a little hard but just spin it around and slowly pull... bingo!
now this is the part where you would change your bearings. i got bearing kits from repco at $30 side. they come with instructions and i recommend that you follow them. expect some hard work getting the races out of the hub!
grab your rattle gun (oh yeah, you're going to need it these fkn bolts are tight!).
now grab a beer and give yourself a pat on the back, you made it this far!
grab your new disc's and clean off the anti-rust protector.
line up the holes and start of the screws. remember to tighten in a star pattern.
now just do all the same steps in reverse, re-grease everything and you have saved yourself some coin!
i hope this is easy to understand and gives you an idea on changing your disc's and bearings. special thanks to marco for the rattle gun and greg from GSL rally sports for the discs and pads.
as noted by the wise men below i forgot to talk about tightening the nut up. it is important that you do not over tighten it. if you have a torque wrench it is probably a good idea to use it and tighten to toyota specs. i simply tightened it until it "binds" then back off a tiny bit. the wheel should be able to spun by hand with some resistance.