WiX - Doing a major upgrade on a multi instance install

Question

So, I have a windows service which can have multiple instances installed on a single server. The installer needs to be able to upgrade a single instance. The installer uses

Answer 1

Here is what I've done so far to handle 3 separate instances upgrading:

While my Property Upgrade is a fixed Guid. With this, I can handle 3 instances with their updates separately using this line -for new installs, add MSINEINSTANCE=1- :

msiexec /i MyProduct.msi MSINEWINSTANCE=1 Transforms=":I01"