When installing a new clutch, undoing the axle nuts while the wheels are on the ground makes things easier. The axle nuts are torqued really tightly and staked so this is a great tip!
On a WRX the top bellhousing bolts are easy to get to on the top side as the engine is pretty forward in the engine bay due to its north south configuration.
The driveshaft is removed and the front axles, slave cylinder and lower bellhousing bolts. The transmission is supported with a transmission jack and the crossmember bolts are removed.
The transmission can now be lowered.
The stock clutch and flywheel are now removed.
The ACT Streetlite flywheel is now bolted down.