Well... I'm not sure exactly- but you could right them a note asking them to use they/them pronouns for you... I've came out a bunch of times, and it's been either over text or in a note every time- When I asked my parents to use they/them pronouns for me it was in a note, My family really struggles not to use she/her pronouns for me, and I feel uncomfortable when they do, but they're trying to use they/them pronouns for me and correct themselves a lot... I also recently figured out I am either trans masc or demi-boy so I've been experimenting with pronouns and I want to tell them to use he/they pronouns for me but I haven't brought myself to do it yet... You know what- I'm going to take a piece of paper, draw the trans flag and write a note for them! I've done this before, and it seemed to turn out well- so... Ya!! Also- Good luck to you!! :))))
-Ash