Of course you can fire them, as long as you can afford it.
But the employer can then still refuse to take the employee back. In that case the employer owes the employee 6-32 months pay in damages, and the employment contract becomes legally terminated.
Source: The Swedish law on employment protection, paragraph 39:
"Where an employer refuses to comply with a judgement by which a court has annulled a dismissal or redundancy or has declared a fixed-term contract to be of indefinite duration, the employment relationship shall be deemed to have been terminated. The employer shall pay damages to the employee for his refusal in accordance with the following provisions."
Fun fact: managers have their own union in Sweden as well! ("ledarna", literal translation: "leaders") And as the other commentator mentioned, you'd most probably lose your position as the company if you participate in bullying, and if your union finds out, you'll most likely get kicked out of the union as well.