Firmware upgrade on Cisco WLC 2400

this is my first time doing a firmware upgrade on Cisco WLC, I have few questions. I notice there are two image files in Cisco firmware page , 1.base image 2.AP Bundle image

Would this procedure work?

1.Download base image onto WLC, and do not reboot yet

1. Download AP Bundle image onto WLC, go to WLC, under global-config, pre-download AP image.

2. Reboot WLC

or do I have to follow the exact procedure outlined in release notes ,

1. Download base image onto WLC , pre-download AP image, and reboot
2. Download AP bundle image onto WLC , pre-download AP image again and reboot

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I'd like to stick with rebooting once, but I am not sure if this could pose any issues? Also, when AP pre-downloads the image, does it use base image file or AP bundle image file??