How do I switch from CCS 3.1 to CCS 3.3?

We need to know how to change vissim+ccs 3.1 to vissim+ccs3.3. CCS3.1 and CCS3.3 both are installed in same pc. Please advise

Download the latest ECD and reinstall

Easy method

Do not uninstall your current version, simply download and install the latest ECD on top of your current installation and it should automatically update necessary files.

If you want to edit by hand

If you have an F28xx target, edit \vissim70\dsp\dosrun28.bat in notepad, and change the first line from:
set CG5DIR=C:\CCStudio_v3.1\C2000\cgtools
to
set CG5DIR=C:\CCStudio_v3.3\C2000\cgtools

If you have an LF240x target, edit \vissim70\dsp\dosrun24.bat in notepad, and change the first line from:
set CG5DIR=C:\CCStudio_v3.1\C2400\cgtools
to
set CG5DIR=C:\CCStudio_v3.3\C2400\cgtools