Just run "Deinstall Kernel-Power" from the Maemo application menu to uninstall kernel-power. To install kernel-bfs: download the .tar.gz containing compiled deb files, extract it and install the .deb. files.
Command to extract .tar.gz: tar -xzvf kernel-bfs-maemoXX.tar.gz
Command to install .deb files: (as root) dpkg -i XXX.deb
To install all debs at once: (as root) dpkg -i *.deb

In my previous post I've only provided a pre-compiled kernel-bfs equivalent of kernel-power 2.6.28-maemo42 because most users don't want maemo45. Here's a link to the pre-compiled equivalent of maemo45 as you've requested it:
http://members.upc.nl/m.groenen60/ke...maemo45.tar.gz
Please only use this if you explicitly need U-boot and/or hostmode, otherwise stay with the more stable maemo42 (as per Titan's suggestion)

The BFS scheduler . Google it to learn more about it. A good starting point is the FAQ made by the author of BFS (Con Kolivas): http://ck.kolivas.org/patches/bfs/bfs-faq.txt
There's also a Wikipedia page of it, but the link would probably be censored, so you'll have to google it yourself