Any way to remove partitions on Asus zenbook
You can use the excellent/free program called Minitool Partition Wizard (http://www.partitionwizard.com/download.html - I used it to do this very same function on the Samsung 840 Pro 128GB SSD Win7 boot drive that is in my desktop system.
Remember that you can only expand an existing partition into space that is physically adjacent to it. The expansion process takes some time so don't get nervous while it is happening.
I have the same laptop - it is great, right? So far I have not merged the extra partitions on the laptop because doing that eliminates the possibility of doing a "Refresh" in the event of some sort of software catastrophy.
My laptop currently has 58GB free which is not a lot, but should be enough to hold all the pics & videos from our next trip to the Greek islands. Even though I only use the laptop when travelling for backup & email and not for "real work" I have installed Office 2010 Pro, Photoshop Elements, Sony Vegas Movie Studio, and Autopano Giga.
To make more room on the SSD I deleted almost all of the Win8 Metro apps - there are about 2 GB worth of them - (doing this is not exactly straightforward) and installed a utility program called Start8 that brings back the normal Windows Start button etc. So the Zenbook looks and functions like Win7. (My wife could never deal with Win8's weirdness, and I don't want to either.)