Many Honda and Acura enthusiasts seek more power from their cars. Some of these engines are easily swappable, some are more challenging, and some are simply too difficult to be reasonably worthwhile.

[edit] Steps

Choose your engine.
Order the necessary parts.
Organize tools and write down a plan.
Prepare the donor engine to be installed.
Remove your previous engine, making sure to label all re-usable parts.
Hoist your new engine up and into the engine bay of the engine recipient.
Hook up all components required for the new engine to be installed.
Refill fluids for all major components of engine, transmission, and coolant systems
"Break-in period" should be 500 miles or so of easy driving (under 3k rpm)

[edit] Tips

Removing the pin which holds the shift linkage to the transmission on most older honda/acura cars is often the most difficult part of a swap. It is worth your while to purchase the correct punch for your vehicle. (My '91 CRX and '90 Integra were both the 8mm punch)
If you purchase a used engine, it is often a good idea to replace any belts, the alternator, and the clutch while the motor is out of the car.