with just some pliers and a good quality 9v battery you can open a 9v battery without damaging the internal cells so they can be used as a replacement AAA battery
oh and by the way THIS IS NOT DANGEROUS you are not opening up a cell you are opening up a battery (batteries have cells joined together)
Step 1: gather your tools and materials
go and grab your pliers and a good quality battery. I use a energizer battery but a Duracell might do it as well.