Can i use chi square test to remove a particular variable from the model?
What you described is the Filter Method. One of the three methods of Feature Selection. The most common mistake that one could do is to make the feature selection as an independent step on your whole process and then decide which model he will use. The most appropriate way to do it is to include your Feature Selection process in your accuracy test and try different kind of feature selections. The best way for the feature selection is the domain knowledge. If you don't have it, then you start working with one of the three methods, like the Filter Method.

What you need to do is to test the chisquare or mutual information on your features with your label column. This will give you which of the features have low effect on your prediction and you can remove it.

You can find a briefly detailed article about Feature Selection here and here.