Installing an antenna is something that many choose to do themselves, without calling in professionals. It's definitely possible to do yourself, especially if you have any experience of doing it before. This could, however, be a very dangerous procedure, as all work should take place on the roof. You can place an antenna in your attic, but it's not advised. To get the best signal, you should place the antenna on the roof, and when you do, there are some safety procedures you need to keep in mind.
The first thing you should do to make sure your antenna installation is as safe as possible is to consider where the nearest power lines are. This is of crucial importance, as the power lines could injure you severely, or even kill you, if you were to touch them. Make sure you keep a safe distance from any lines hanging in the air, as you can't be sure if they're harmless. This is also important because you don't want your antenna to crash in to them if it were to come off during a storm. For this reason, you shouldn't mount the antenna higher than the power lines even if it's installed at a safe distance from the power line, as it can come crashing down on them.
What gear you're wearing is also important to keep you as safe as possible. You should wear shoes with a thick rubber sole to ground you in case you were to be electrocuted. You should also wear rubber gloves, but make sure they're as flexible as possible so that you can do all parts of the installing without fumbling. Lastly, you should wear clothes that cover your entire body, to not expose any skin to possible elements that could give you a shock.
You should have someone with you up on the roof to help you with the installation. This is especially important if you plan to get an antenna mounted on a pole, as this needs to be erected and therefore demands assistance. Make sure the one helping you is also wearing proper attire. If something were to happen to the helper, like if they would get electrocuted by a power line, you should not touch them or the power line. Pry them off the line with a material that isn't affected by the current, like a dry piece of wood. Check their heartbeat and get them off the roof as soon as possible so that they can be taken to a doctor.