How can I tear down the wall between dining and living room?

Be sure the wall you want to tear down is not a load baring wall.

Bring in a contractor to look at it. You must be sure it is not a bearing wall, meaning it's necessary to hold up your 2nd floor/roof. If it's not a bearing wall, try to determine also where the electrical lines are so you don't accidentally cut them. Have the contractor tell you if the HVAC runs through that wall. If it does, this is likely not a DIY project.

If it is not a load bearing wall, you will need an electric reciprocating saw to not only "tear down" the wall, but to cut through the lumber, and sometimes steel brackets, that are behind the wall. If there are any plumbing pipes, electrical wiring, or HVAC ducts, then these will have to be rerouted, hidden, or re-accomodated as the wall is coming down.

You will also have to consider what you are going to do to finish the empty strip on the ceiling, and in the floor, that will result when the wall is down.

While the job is possible, it is not simple, and it is extremely dirty. Wear a mask and goggles to protect your eyes and lungs from breathing in the dust. Be prepared for drywall dust to be on everything.

It's really important to make sure that the wall you want to tear down is not a load-bearing wall. If you don't know how to do this you may need to find someone who is an expert in this like a contractor to determine that it is not a load-bearing wall on the home you live in. Once you determine it's not a load-bearing wall you can simply remove the dry wall and any vertical pieces of wood within the drywall. It's a simple as that... But it's really really important that you make sure it's not a load-bearing wall, as you will create a huge expensive dangerous situation if you do decide to take down a load-bearing wall without being aware of it. Good luck with your project and I hope this helps.

First make sure it is not a supporting wall, then clear everything out of the way and start hitting the wall with a hammer. Really, I decided late one night to know out a wall. I used a hammer and cleaned out the sheet rock. The next day, I used a crow bar and hammer and removed the studs. I did it and I was so proud of myself.

make sure it is not a load bearing wall. if it isn't then yes you can

Contact a licensed residential contractor before proceeding! Get proper guidance before doing anything as the result can be catastrophic.

Before you tear down any wall, I would advise you to see if it is a load bearing wall.

you will have to find out if its a load baring wall first which means a wall that bears the weight of the house resting upon it by conducting its weight to a foundation structure.. if its not get a sledge hammer and start knocking off the exisiting wall, and when you have removed the opening you want. frame it off with wood and paint it