It is very unlikely that you will need the help of a professional to install a bioethanol fireplace within an empty fireplace. Most freestanding bioethanol fireplaces come fully or partially assembled.
Do bear in mind the recommended safety distance around the fireplace (usually 5-10 cm from non-flammable materials on any closed sides and 1m from flammable materials on open sides.)
It is then simply a case of filling your bioethanol fireplace with bioethanol fuel.