[Mediawiki-l] I could upgrade, but...

[Azurite]

Hi all,
I found out my shared server finally has PHP5, which means I can upgrade 
to the latest version of MediaWiki-- sounds like a good thing to me, 
since I've been hearing that there are lots of extensions (like the ones 
I've had trouble with recently, like the ParserFunctions) that work 
better in the later versions, rather than the version I'm currently 
running, 1.6.10.
However, my server specified something interesting with how PHP5 is to 
be selected:

In order to utilize Php5 simply save all of your files using the 
extension .php5

If you wish to use solely php5 and not php4, instead of having to save 
your files using the extension, simply add the following line to your 
.htaccess

---
AddHandler application/x-httpd-php5 .php
---

And this way all of your files will default to php5.

So if I want to upgrade my existing version of MediaWiki to the latest 
stable version, how can I do that? Will doing the *.htacess change mess 
up my existing MW 1.6.10 install? Or can I somehow use the .php5 
extension when upgrading?
Thanks,
-Azurite