An easy way? I'd say no.
A .zip update like this simply install (or overwrite) different .apk files (this one is simply called Gapps because it contains most of the google applications that are included with phones). You could always use an application like root explorer to remove them (if you still have the original Gapps you used it should be easy and easier if you use ADB). Or you could use a script in the form of another .zip package but it would have to be adapted to the specific Gapps package you used.
Why would you want to do that in the first place?