i'd tend to go out the top. get a crane, remove the rad to give you extra room to manovre, and lift engine and box out the top. Swap the box over on the floor (new clutch). The back in again.
A few notes:
Make sure you've got belt history on the new engine, or preferably, get the tools and do the belts before starting the swap.
If your clutch has seen any kind of reasonable use, you'd be mad not to replace.
You'll need a smooth floor, for jacking, and particularly for the engine crane.
You'll want a mate to help, even if they are quite inexperienced, it will help.
Have a good ol reccy the day before you start. Decide how your going to disconnect PAS+AC
You'll need the AC regassing after your done, and be aware that releasing the AC gas to atmosphere is technically ilegal.
As far as the engine loom goes, it can be usefull to have a few photos. But normally, for refit, just lay the loom back over the engine how it went and it should become fairly obvious where everything went.
You'll need a 30mm(iirc) socket and a massive breaker bar to get the hub nuts off. It can be avoided, but it's really not easy. - also it recommended you have new hub nuts for refit.
You'll need gearbox oil. You'll need coolant. You'll need PAS fluid.
Don't just give yourself a day. Make sure you have some free time the day after, even though you may not need it.
Hope that helps