I would recommend leaving the purchased installer version as it is. - The recent changes to Jim's betas from fish-byte.com will be included in the official version (ie. the one from SereneScreen), in due course, ie. when the bugs are sorted out.
The easiest way to "Install" one of Jim's betas (if you must!
), is to simply right-click on MA3Beta.scr you just downloaded and click on 'Install'.