really, it requires a ramp so you can stand underneath to undo some bolts, as some are quite tricky when you're on your back (never done an almera one), and then you have to drop it out, and if the car aint high enough, you mightn't get it out at all, but it is a 2 man job, as some gearboxes are very heavy
i have worked on a fiat bravo, and with axle stands, it managed to slip out but it was akward to get to, you had to remove loads of crap in the way lol