Upgrade Procedure from 0.9.1 --> 0.9.2.1 ??

Can Someone please explain what steps I should take to upgrade to 0.9.2.1 from 0.9.1.

Do I need to overwrite my existing directories for manager and assets and copy across the install directory from the zip file into my existing site?

Any help you can give much appreciated as I am unsure what the fastest and least problematic way of doing this is with doing a completely fresh install and then copying all the assets etc across.

Well, anselm1109 has produced a good document with step by step instructions on how to upgrade - check out the following thread for the link:

http://modxcms.com/forums/index.php/topic,4220.msg30809.html#msg30809