a question about genre

Hi! I have a question wheather to use him or her, or if I should alternate them, or just use the plural. This is the context:

In the case of transference of Business, the employee shall only consider themselves/himself to be dismissed when they/he suffer/s damage due to the transference of business, for instance: a change in the object of the company, a change in the employee’s tasks, etc. The cause invoked by the employee to considere themselves/herself to be dismissed.....

hope I've been clear
Thanks!
PS, the original is in singular -EMPLOYEE-

If you want to use plural, you'd have to change the whole text: "...Business, the employeeS shall..." I'd use himself/herself&, he/she.

ok Danielm, thanks for your quick answer!!