I believe that you install UPlay on another PC and login to your account and it gives a list of games associated with that account which you can download. In there you should find the installer/downloader that Steam used to download and install Uplay when it installed the game. Run it and let it update. EDIT: I had no trouble finding the installer through that orange tab on the site.
Uplay and Incremental Updates
So I just purchased Splinter Cell Blacklist for which you need the uplay client and I noticed something which is kind of hilarious in my honest opinion. I want to ask /r/Games if I am the only one who is bothered by this.
Here is my problem:
-If you download the Game you first get basically the version of the game that was first published. Which is fine.
-If you now want to play it uplay will start downloading the first(and only the first) update.
-After this download is finished you have to install the update via a wizard(installer).Which is still kind of fine I guess...
-now you can play the game without updating anymore as long as you don't close uplay(which is strange because now you play on an outdated version)
-The problem is you have to do this every time for every update that has come out for this game since it's been released. And it will only install one update each time you start uplay! I so far spend an ridiculous amount of time installing and waiting for these updates one after another and there is no end in sight... (so far I think I had to do this at least 5 times which is strange since there should only be 3 updates...)
I think that this is a very bad design choice of the uplay client! Just install all updates the first time the game launches. And I think that the installer is kind of senseless... what could you possibly need to change about the installation of an update... There are no choices to be made here! look for example how steam does it. You don't have to bother about hundreds of stupid time wasting installers there! It all goes automatically without needing the attention of the consumer. And btw I did notice this behavior for other games other then SCB.
Am I crazy on this?
Where Does Uplay Download Game Installer Tool