Hi there,
what you can do is to go to your deployment management and find the deployment in question.
I don't remember the exact location but either on [right-click > properties] or by expanding it, you will be able to see all the updates that got deployed.
then you can choose the update that you want to remove.
OPTIONAL:
to be safe, you can delete the actual, downloaded update directly within the update package itself (needs to be done AFTER you remove the update from the deployment management) so when the client tries to download it, it will give an error that the item can't be found (or something like that)
regarding the client, that's a bit tricky since the ccm agent is the one that initiate the update scan so there's not much you can do about it.
but as long as you don't change the default settings of the agent, it is by default do a scan every 2 days.
so as long as the client pc is turned on for at least 2 days, it should be able to get the updated list, which has that particular update removed.
just curious ... what kind of problem you're having with that rdp-client?