Congrats on making up your mind!
This surely is a big step for anyone to take. I can imagine that you can see yourself pulling out last minute.
You have the right to live your life as you see fit.
You are not responsible for other people's happiness, only your own.
If people choose to feel sad or angry over your choice of religion, that is entirely up to them. That is not your burden to carry.
I do agree with other posters on some points.
1) Doing this right after the memorial makes the event a yearly painful event for friends and family. It also (somewhat intentionally) puts a downer on their yearly religious high. So if you do this, do it today. Or on some other non-specific date. It's more kind to everyone.
2) DA or not DA doesn't really make a difference in your status to Watchtower. Watchtower doesn't have a centrally maintained membership list. If you DA, both the local congregation and the branch office will keep a record of your DA. If you don't DA, only your local congregation will keep a record of you being inactive. Either way, a record is kept somewhere. DA serves no real purpose, except perhaps for giving you closure. In that case, consider writing a DA letter, put it in an envelope, but don't send it. Or send it to Bethel without identifying yourself. Remember that when you DA, your family must shun you. If you don't, they probably will, but they don't have to if they choose not to.
An alternative to DA is to quit cold Turkey. Simply stop all JW activity. Tell your friends and family "I can no longer in good conscience attend JW meetings or go to field service." When they ask for details, tell them you are willing to share your reasons if they promise confidentiality. If any elders call or text, politely but firmly tell them to get lost. This scenario worked somewhat for me. Most JW friends dropped me anyway. Some JW family too. But a few friends and family are still in touch, which they wouldn't have if I DAed...
Anyway, regardless of all our opinions, do what you know needs to be done.
Good luck to you! I wish you wisdom, calmness and strength to go from pimo to pomo. You deserve to live as you see fit!