I just went through this with my bike (sorry, it's not an FZ) and it's pretty straightforward...
The short of it, is you disconnect everything, unhook everything, place a jack underneath the engine, loosen the mounting bolts, and lower the engine.
Installation is opposite of removal. If you've done a lot of work on your bike, and are comfortable with processes such as rear wheel alignment, front sprocket removal, exhaust removal, etc, removing the engine is just a further step and not very difficult. In fact, the overall number of fasteners of which you need to keep track, are not many.
My first removal took around two hours, and the installation took around three (I was very cautious). To do remove my engine again, I think I could have it out in a little over an hour, and back in...maybe two?
The bold points?
Work in a well-lit area.
Make sure you work in an area where you can leave the bike, if you need to. In other words, don't work on it in an area where if you ultimately don't remove the engine, you're screwed, because the motorcycle is behind your car, or something like that.
Take your time. Don't be afraid to walk away. This is especially true during re-installation, when you have to be more precise. When I get stuck, I walk away. A breath of fresh air will do wonders for your psyche.
Any fasteners you remove, place in plastic zip lock bags, using a Sharpie, mark the bags with what the fasteners are for.
Take pictures as needed. The stuff that comes off so easily can be easily forgotten, when it comes to buttoning it back up.
Drain the coolant and oil before starting.
If your jack is of the cheap kind, and does not have a rubber protector pad, get a small piece of soft wood to use in between the engine and the jack (you don't want to scratch your engine).
When you actually remove the engine, it's a good idea to have a friend nearby to assist. An extra set of hands is a great thing.
Remember which cables are for which. If needed, use some masking tape and label each cable (like the throttle, and return cables).
In the past, I've kept a log of everything I've done. I've found this helpful when I've restored cars, that way, I can go back and read a step-by-step of what I did. If needed, it can really jog the memory.
Before re-installing the engine, do any maintenance that is difficult when it's on the bike. That can be from items as basic as cleaning the engine or the frame, to procedures like valve adjustments.
Good luck!
