Hi,
If you are referring to 3.11.2 version of zeodha trader, you need to uninstall the old version & delete the omnesys folder in C programme, then install the new application as explained in the given link below. Note there is no change in the installation steps its same.
http://zerodha.com/z-connect/tradezerodha/zerodha-trader-software-version/zerodha-trader-installation