Congratualtions Mrs Minimus and welcome (even if you are just reading at this point)
I too had to make this adjustment. In my case it was really weird. I left 15 years ago and in that time another uncle and his family left and I had not seen them in the 15 years since I had left. Another aunt had BECOME a JW in that time
On my way to moving across country I stopped in their area and my aunt who had BECOME the JW was having a get-together for her son and the family who happened to be in town at the same time. I had not seen any of these cousins since I was a child. I had no idea how they would react to me if I showed up. It was such a mixed bag - never-beens, just becames, and DFed and DAed and true blue apostates like me.
Well I walked in and was greeted by such warmth and love. When my recently left aunt and uncle walked in she came over and grabbed me. We just sobbed in each others arms. My JW mother who was there had to leave the room so she wouldn't show how she felt about our reunion but every single other person there - JWs and non and ex where so pleased for us and so welcoming.
It was the most awesome display of unconditional love I have ever experienced. It was family and it was wonderful.
Explanations could be made before (you have time before the holidays roll around). Apologies for the lost years and a desire to learn about these family times and how you might need some assistance in learning the ins and outs of them. Some might have some anger at the lost years but the ones you would want to be close to will welcome you with all the love they can muster and it won't be conditional. Its been there all along - just all those stupid rules prevented everyone from showing it
Give just one a call and let them know about the changes and see what happens. I bet you will receive an avalanche of love and welcomes to the real world