Hi DR,
I started reading your OP and notice my story is quite similar: pioneer, have gone to college, serving in a foreign language congregation... I am also a MS for the moment.
I think you could do it step by step. First of all, quitting pioneering was of great help for me as I had suddenly plenty of time to think, dedicate to my career and do non-JWs things.
Then, I stopped doing the trolleys and started missing some meetings now and then.
Now I'm at that point. At first, I have to tell you that you'll disappoint brothers when you stop being a spiritual pillar of the congregation but it's a matter of time (less than you think) until they come to terms with it.
I'm planning to move to another "normal" congregation after summer as you'll know it's hard to fade in this kind of zealous congregations filled with pioneers and zealous witnesses.
Hope all will be fine in your fine. Just try not speak too much because elders and others will try to ask about your reasons and motivations. Don't explain just tell them you need time or are busy and you don't have circumstances to keep serving at that pace.