Ive re-celled quite a few batteries in my time, but when it comes to laptop batteries id just rather get a gneric brand replacement or at least see how much a place like batteries + would charge

re-celling them is not the hard part, getting the !@ cases apart without destroying them is

as far as your floppy goes, yea they are spring loaded, if they dont catch that means either something is bent/broken or just jammed up inside

you should be able to carefully remove the drives cover and inspect its workings for mechanical flaws, just mind the read/write heads ... other than that they are basic mechanical devices