If you take the staple out, you could manual restaple it by carefully putting the staple throw the two wholes and bending them inward couldn't ya?
Yes, and if the staple breaks just use another one.
You know, in theory, that sounds all nice and easy.....
However, I have tried it and unfortunately things just never seem to work out that easy. ( I ended up with a manual with oversized holes and loose staples.)
You have to do them by hand, as most manuals will not fit in a normal stapler without folding the cover - and then you end up with a big crease in your cover.
It is simple enough to cut and paste from a high quality .pdf to create a printable cover, (I have done this many times). Once you do it a few times, it's actually pretty easy. I don't know about using microsoft paint for this, you will probably need to invest in a better quality graphics program. I use Photoshop Elements.
-or- you could just buy replacement manuals from the manufacturer or eBay (which is where I get most of mine, that you are now suggesting that I pull apart and put back together.
Sorry if this sounds harsh, that was not my intention, I re-wrote it several times.