I replaced my clutch last week because the notorious throwout bearing went to junk. There's a couple great threads on all the steps for the job, but they all mention angle iron or wedging something in the flywheel teeth to hold it in place, and none showed how (that I could find). In any clutch job I've done, this has always been a bit of a figure it out in the moment thing, and usually kind of annoying.
Well, for the BRZ, use the old throw out bearing that you just took out of the bell housing. It fits right in at 10 oclock on the flywheel. Just apply a little pressure to it so it doesn't drop out while you loosen the flywheel bolts and when you're torquing them back in. Easy peasy.