Ignition lock cylinder replacement ??

I have a 92 Integra LS with automatic transmission. It got stolen the other night , but luckily the cops found it with the engine running a few hours later. the thief popped the lock cylinder out and started the car with a screwdriver. when i look at the ignition switch it looks like I only need a new lock cylinder but the helms manual says (on page 23-59) that i need to replace the whole steering lock assembly :argh:. Does any one know if I MUST replace the the whole assembly as the Helms says or I could just buy a lock cylinder? I can get a lock cylinder for $90 vs the whole assembly for $270. i hate :gun: thieves !!!