This is not a diy project. Call in an expert.

You need to hire a structural engineer to make sure the walls aren't load bearing in which case you need to put in a beam to support the roof.

Please please hire a professional to at least tell you if said wall is load bearing. If it isn't and can come down then you need to also look for electrical wires and plumbing lines. Making a small hole with say a hammer and then start pulling dry wall off by hand. If you saw through it there is the chance of electrocution or cutting a pipe and flooding. Are you prepared to repair drywall where two rooms will connect. Repair ceiling also? A lot more involved than people think.

thank you. this is very helpful