Removing Lift

Removing the rear axle spacers would probably do the trick there - direct relationship to the height. Down she goes. Be aware that many of these trucks that have had to work for a living - have some droop to the rear springs.

The diagram above shows the effect of preload on a front adjustable shock. Bilsteen 5100 I'd expect. Take a look at your outfit with no driver and a tank of gas - head on, flat pad. If yours is behaving like mine has - "Taco lean" to the driver side. If you install the new Bilsteens (with no lift spacer rings above) and use the stock (#1) shock setting on the passenger side - and the #2 setting on the driver side........ it will typically square things away.

Then go get a good alignment.