It is not easy to replace turbines. I explained this. It really depends on the technicalities of the pipeline. Certain technical parameters need to be met, and for that you need to have a special fit. It's a very long design period to design compression stations and design the size of the turbine.
Replacing existing technology with something else is a large undertaking that you could probably compare to a new build. Those are very expensive and very time-consuming or lengthy activities.
I hope that answered the question.