@unknownuser said:

Insert it anywhere or somewhere specific?

Where you put it doesn't matter. Just open the file and you'll see
a bunch of other entries that look like the block of text you need to
insert. If you're using an editor that doesn't format the text so that
you see other blocks of settings like the one you need to insert, try
write.exe. Do Windows Key->r to open the run dialog and type in
write.exe and then open preferences.xml in there.
For example it would look like this after you insert-

<t:dicItem key="read_old_file_version_warning">
<t:variant type="1">0</t:variant>
</t:dicItem>

<t:dicItem key="render_ST">
<t:variant type="1">1</t:variant>
</t:dicItem>

<t:dicItem key="su_render_hybrid_warning">
<t:variant type="1">0</t:variant>
</t:dicItem>