There are some websites which help us to select similar transistors; I have used the alltransistors.com (there are others), which you can use to make the first approach, and if you don't find anyone, it is possible to adjust some parameters from the original transistor in order to increase the options, as for example, if you find few transistors compatible with the original transistor, and if its breakdown voltage could be decreased, you change this parameter and will see much more options to replace.