It sounds like you have it fairly well figured out already. a 740 B230F is, in my experience, the easiest car to put a timing belt on. Three hours should be plenty of time, even if one or two minor difficulties crop up.
To remove the crankshaft bolt, you can put a socket and breaker bar on it, wedge the other end of the bar against the floor (remebering that the engine turns clockwise as seen from the front) and hit the starter briefly. Use the rope trick to hold the engine when you reinstall and torque the bolt. When using the rope trick, make sure cylinder #1 is at TDC----it is important that both valves be closed when you do it, otherwise damage can occur.
The crankshaft pulley usually comes off easily, if you pull it perfectly straight. If it doesn't want to move, get two identical length screwdrivers, put them behind the pulley, on opposite sides, and pry with as equal an amount of force as possible. Be aware of what you are prying against on the engine to avoid damaging anything.
I have often found the most difficult part of the whole job to be removing the four 10mm nuts that hold the fan clutch to the water pump flange. They are usually very tight, and prone to rounding off. This problem is compounded by the fact that there is not enough clearance to get a box end wrench onto these nuts, so you have to use an open end. The last time I did one, I used a Snap-on, which was a tight enough fit and strong enough that the jaws don't spread under stress, and all four nuts came right off. This was not the case on some previous jobs, where all I had was Craftsman or an even lesser brand---the wrench slipped, one or more nuts got rounded off and it turned into a major hassle. If it gets really bad, you can sometimes use needle nose Vise Grips to get the nut loose. Then you have to find a replacement nut. You want the flanged kind for its extra clamping power.
The advice others have given below about replacing the seals is good. If they are at all suspect, now is the time to replace them.
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