It's not too bad to do but I've only done it on a ramp with a transmission jack and extra hands.
You'll first have to remove the exhaust, prop, suspension and brakes etc, you'll see once you're under the car what is attached to the car that won't come off or is in the way.
Once these are off, there's 2 sensors on the diff at the back, both have 1 12mm bolt. Once these are out the sensors may need a gentle tap to free them and can be pulled out and can let them sit on top of the diff. There should also be an earth from the subframe to the chassis on the rear passenger side (these are usually corroded and not actually connected, but should be replaced when re-fitting).
Depending which car you have you will need to remove the hicas pump, it's usually easier to unbolt it and zip tie it up out the way whilst you're lowering the subframe. Haven't done this in a while but iirc it's 3 or 4 12mm bolts at the top out of sight.
There's probably bits I'm forgetting but it's fairly common sense one you start tackling the job.
To remove the subframe, you'll need to suitably support it on the diff and if possible support from friends on either side to stabilise it.
There is the main 4 17mm bolts for the subframe to remove and usually a brace that comes from the rear of the subframe to the front with an 'L' shaped bracket at the fronts. These are attached through the main 4 subframe bolts and 8 14mm bolts/nuts.
These more often than not are usually ceased so take caution as you do not want them shearing off!!!!
When all these are removed you should now be able to slowly lore the whole lot as 1 complete unit