Its hard to walk away from friendships but I found that over time, the hardcore JW friends I had couldn't handle any doubt cast on their beliefs and it was easier to part ways.
I find that true. I "stepped down" 25 years ago and started my doubting phase about 5 years later. Then took another 10 years to completely fade. I had one elder friend (elder in both ways) who kept in touch and we exchanged calls every couple of months. That final phase finally ended a year or two ago when the calls stopped.
I wonder what keeps him going as he is an intelligent guy and has witnessed all the same issues that caused my doubts, but he's still there. Most of his children are PIMI, so he has that at risk if he would leave, but at 80-ish, "where would he go"?