I did precisely this today and found the answer in an older post. The procedure is a little easier than you suggest:
Go to Tools-> Game Settings
Check game type is D&D
Go to miscellaneous tab
Click the Reload button beside the combatant look-up.
This is the main draw of initTool for me and I feel that it needs to be right there on the front page - not buried in the miscellaneous tab of the game options settings.
Would it be possible for initTool to ask the user to specify their rules system the first time it is installed? If the comabatants were loaded as part of this process it would do it once and for all.
The real problem here is that there shouldn't be a procedure for new users. I've created a tracker to fix this.