Oh, I think I misunderstood.
So you have two different Bigfix deployments, one was an ILMT and you need to move clients off that deployment onto a new one?
That operation is known as a “masthead switch”. You don’t actually need to uninstall or reinstall the client at all. What you would do is use the old deployment to send an action that switches the client’s masthead file to use the masthead for your new deployment. When it restarts the client, the client stops reporting to the old bigfix server and starts reporting to the new one.
I think there’s a masthead switch task in the BES Support site, with instructions for how to load the new deployment’s masthead file. Let me know if it’s not there and I’ll find the instructions.