The way I got off 25 years of 150mg Effexor (venlafaxine) was:
Cold turkey. No! Had a long, terrible experience.
Started again at 75mg.
Once I had stabilised, bought a 4-weekly pill dispenser and a pack of empty capsules.
There are 6 little white pills inside a 75 mg venlafaxine SR capsule.
Set one pill aside for the first 10 days, leaving 5 little pills in each capsule, thus reducing from 6 to 5. (used the original capsule). Marked the dispenser on the day I reduced the dose. Very easy to forget.
Set two pills aside for the next 10 days, leaving 4 little pills in each capsule, thus reducing from 5 to 4. Marked dispenser on the day I reduced the dose.
Then set three pills aside for the next 10 days, leaving 3 little pills in each capsule. Marked the dispenser.
Then set four pills aside, leaving 2 pills and got a strong reaction. Google said, talk to your doctor, but he didn't have a clue. Fortunately a student doctor explained ratios and fractions in stepping down from 3 to 2, instead of the gap between 4 to 3, so I went back to 3 little pills for 10 days, and stabilised, followed by 2 1/2 for 10 days, then 2, then 1 1/2, then 1, then 1/2, (when I needed to use the empty capsules) then an approximation of 1/4, manipulated with eyebrow tweezers, followed by crumbs and kept on at that for a couple of weeks until I decided that this was silly, so I stopped. Clean!
I'm posting this because, back then, I really needed to know it was possible to stop, and found nothing. It is possible. I've done it.