BB 1.1 switching kernels from Rom Manager help

Hey guys, I'm running BB 1.1 1.2 ghz 1.2 IV. I want to switch to the 1.1ghz LV and see if I get better battery life. Can I just go into Rom Manager under BB 1.1 and select the new kernel I want? Only reason I'm unsure about this is because it also asks me for what theme I want. If not this, is there another place under Rom Manager I can go to to get a lower voltage kernel? thanks

 

Okay cool, once I download that, will it prompt me to flash the kernel? I know I keep the same rom and nothing gets deleted but just making sure I know what to expect.