If you inherit a difficult employee, deal with the situation as quickly as possible. Behind a difficult employee is a history and possibly a complex personality that you don’t yet know. In order to get as much background as you can, consider meeting outside the office (coffee/breakfast/lunch) to get to know the employee. This can help you understand them better and determine how best to manage them. If appropriate, be up front and tell the employee you feel you got off to an awkward start and you want to discuss how the two of you will be able to work well together.
If the employee is good at what they do, it is probably best to keep them rather than replace them. That said, it is imperative that you invest what is needed to make it work. If after a reasonable amount of time it is clear the situation is not going to get better despite best efforts, it may be necessary to replace the employee.
No manager wants to inherit a difficult employee. However, it happens.
Deal with it right away. The problem will not resolve itself and will get in the way of your success, and ultimately the success of the company.