I recently purchased a VY S with a L67 engine and it has been fitted with a front mount air-to-water intercooler from you guys (along with a stage 2 cam package and all the associated bits) and is currently runnning a 14 psi pulley. Whoever installed the

If installed correctly, there definitely won't be any such issues described long term. This I can personally attest to, based on the number of kits which I installed approximately seven years ago without any problems to date. Sadly the parts chosen for this kit, while making it highly functional, also make it tricky to install due to its packaging requirements. To give you an idea as to the installation of this product, please check out the fitting instructions in the link below

 

 

I've stated the above, only that you may be able to revise the current intercooler installation such that you can justify keeping it. Which from a performance perspective is certainly recommended 

Otherwise, the permanent removal of the kit is as you've described, coupled with the reverse of the installation of the intercooler kits as per the fitting instructions. The only obstacle that you may face is if the car has already been tuned to suit the intercooler kit, in which case you would need to get the tune recalibrated without the intercooler kit.