Just did it today.
Ok here's the overview, its really not hard to change rear shocks on a 05+.
You may have to break loose lugs before jacking up wheel. Jack up vehicle. Use a Jack stand to be safe. Remove rear tire. Remove two upper shock mounting fasteners. One is nut and one is bolt.
Remove lower mount nut and washer. Note the washer bows OUT away from shock when reinstalling.
This is the only sort of hard part. Use a pry bar or something to move shock towards end of the lower mounting shaft. The manual says you should use a jack to compress the suspension slightly before removing the shock, and it does help. I had the van on a lift so I only used a floor jack to support the A arm a little.
Pull shock away from upper mount. Using body weight compress shock fully! push shock into open area over top of lower mount. Now the lower shock bushing should slide off the shaft easily since the angle was removed by pushing the top part towards the center of the van. Remove old shock.
Take new shock, compress fully if possible. Attempt to hold it compressed, but it will likely start to expand. No worries, slide bottom bushing over the stud before it gets too long. Guide shock as it expands. You may need to jack up the suspension a little to match the holes in the shock mount with the van's mounting fasteners. Do the fixed stud first, then adjust the jack to align the bolt hole. The two on mine do not align at the same time, the bushing slightly gives so that they can be attached, a bit odd design but it works OK. If you have to rotate the shock to make things line up that's perfectly fine.
Torque upper fasteners to about 35 lbs and lower nut to about 55lbs.
Yer' done!
FYI, the stock OEM shocks had about 1/2 the internal gas pressure of the Monroe Sensatacks. The new shocks give me more "spring" in the rear from the gas increasing the spring rate slightly, but they ride just a smidgen stiffer, but its pretty hard to measure.
This could be done in less than hour for both if you have stuff at hand.