[Mediawiki-l] Changing "Special:Search" and "Special:Upload" pages

[Šerých Jakub]

I would like to change the content of the special pages "Upload file" and
"Search" on my mediawiki server to something like we can see on Wikipedia
(i.e. the "Upload file" page with detailed instructions and licensing model
selection, and Search page whith link to create the nonexisting page etc.).

I found files SpecialSearch.php and SpecialUpload.php in the "includes"
subdirectory and I think, that these files are responsible for these special
pages.

But I'm not php programmer, so I cannot rewrite these pages.

Is there any other way, how to change content of these special pages?

Thanks for any help

Jakub