look at the docs folder,
there are all changed files listed.
Only a few template files were changed.
How to update from 1.71 to 1.72 without losing their mods can also be done,
by comparing a fresh 1.71 and 1.72 with a program like UltraEdit were all differences between these files are listed.
So when you know the changed parts,
you can change only the changed parts,
but of course its better when you know a little bit php and know what you doing,
cause sometimes it affects also parts that were changed through some mods,
so you need to know what you doing.
I wanted to publish first a step by step instruction,
which party a all were changed in the files,
but i stopped cause it's to much to write for me.