One of my better friends and I made a lot of fun of the whole Third Wave Feminism and SWJ movement. He's a bit more extreme then I ever did. And the only side of the Spectrum when it came to transgender people (In real life also, but can't remember was 4) was the SWJ's side of things. Ever since I have met you guys and talked to you, I have also realized that you are such awesome people and how :***: disgusting some of my friends jokes are. I don't know how to tell him since I'm really afraid to tell (mostly men) that I'm gay and stuff. I just feel so bad because I have to laugh/react to it.
You could gently call him out on it next time. Point out that trans people deal with serious setbacks in life (violence being only one of them), and making fun of their situation isn't very kind. You don't necessarily need to come out to say something like this - it could very well just be a matter of empathy. That said, coming out might also give him a more personal reason to reconsider his thoughts on this and other subjects. I don't know what his reaction will be, of course, and ultimately the decision of when to come out is a personal one, but if you feel like you can't come out to this person in particular (as opposed to feeling nervous about it in general), it might be the case that your values are just very different right now.
I'm having a similar problem - I'm at a stage of just not laughing at the jokes that are unnecessarily offensive, and disagreeing with statements to the same effect.
Sadly, some people can't be reached no matter how hard we try. Maybe just say something like "You know I knew/worked/went to school with a transgender girl once, and she was a really great person, and I don't feel she deserves to be treated like that."