1) Verify that you have modmerger framework 0.2.5 (last version since Aug 2010) installed.
2) Add the health_regen_*.py files to the same directory as your module system *.py files.
3) In "modmerger_options.py" add (under the mods_active section):

"health_regen", # Killer Regeneration (1.1)

4) Follow the rest of the file specific instructions listed below. Some of these items
should already be done, but are listed to help catch conflicts.

HEALTH_REGEN_CONSTANTS
1) Ensure that constant "wp_hr_debug" at the very bottom is set to 0. This will prevent debug
messages from showing up in game in case I missed it.
2) IF you want to enable the difficulty scaling feature set "wp_hr_factor_difficulty" to 1.
Otherwise leave it as 0.

VARIABLES.TXT
1) Add the following global variables:
g_wp_player_hr_active # Set to 0 to prevent player regeneration. 1 to activate.
g_wp_ai_hr_active # Set to 0 to prevent AI regeneration. 1 to activate.
g_wp_difficulty # Changes whether the regeneration is better or worse.

2) Ensure that the above variables are set to 1 somewhere or they won't work. Many mods
have their own "mod options" system so that will work
OR add (assign, "$g_wp_player_hr_active", 1), and (assign, "$g_wp_ai_hr_active", 1),
to the end of the "game_start" script in "module_scripts.py" file.

3) "g_wp_difficulty" is intended to receive a value of -1 (easy), 0 (normal), 1 (hard) or
2 (very hard). If you use a difficulty scaling variable in your mod simply replace mine
with your own and change the constant "wp_hr_factor_difficulty" to 1 to enable it. If you
do not use a difficulty setting simply add the global variable (to prevent errors) and
the constant is already set to 0 (disabled).