How to use SVM in Weka?

How to use SVM in Weka?

I'm trying to use the svm classifier in weka. When I click on the libsvm
classifier and try to train a model based on some provided training data,
I get the error "libsvm classes not in CLASSPATH."
The weka website has some information on how to fix this but I'm not sure
how to execute them.
http://weka.wikispaces.com/LibSVM
I got the libsvm.jar file from the link provided. I'm not sure which file
to put it in.
Thank You