Upload all the .php files (except config.php, config_skins.php, config_buttons.php) to your server. If you want to use one of the new skins included with 4.2.1, just upload the skin to your skins directory and it will be available in the admin.
The version number at the bottom of your topsites list won't change right away. To update the version number, go to the admin, then go to General Settings. You don't have to change anything, just press Submit at the bottom and it will update the version number.
Upload all the .php files except config.php, install.php, upgrade-3.2.3.php, and upgrade-4.0.x.php. Don't forget to upload the .php files in the sources and languages directories. CHMOD 666 config_skins.php. Create a subdirectory in your templates folder named Default and copy all the files currently in the templates folder into the Default folder. Rename template.html to wrapper.html.
Download your old config.php. Open in a text editor and find lines 7-9. Change each occurance of $CONFIG['templates_path'] and $CONFIG['templates_url'] to $CONFIG['skins_path'] and $CONFIG['skins_url'] respectively.
Upload the modified config.php.
Templates are now known as skins. To keep using your old skin, you have to make a few modifications. Wherever you see <#templates_url> in any file (wrapper.html, table.html, table_top.html, rate_form2.html), change it to <#skins_url>/<#skin_name>. You must upload the new admin.html to take advantage of the new admin features.
Upload all the .php files except config.php, install.php, and upgrade-3.2.3.php. Don't forget to upload the .php files in the sources and languages directories. CHMOD 666 config_skins.php. Create a subdirectory in your templates folder named Default and copy all the files currently in the templates folder into the Default folder. Rename template.html to wrapper.html.
Go to upgrade-4.0.x.php in your browser and follow the directions there.
Everything should be working now. If you didn't make any major changes to the templates, it is recommended that you upload the new templates directory to take advantage of some new features such as up/down/neutral arrows and alternating colors.
To keep your old templates, upload the new admin.html, lostpw_form.html, lostpw_finish.html, and gateway.html. Templates are now known as skins. To keep using your old skin, you have to make a few modifications. Wherever you see <#templates_url> in any file (wrapper.html, table.html, table_top.html, rate_form2.html), change it to <#skins_url>/<#skin_name>.
Install the script like normal. Upload upgrade-3.2.3.php. Go to upgrade-3.2.3.php in your browser and follow the instructions.
If you want your old members to keep the same HTML code in their website, replace your old topsites.cgi with the new one included in this zip. Just change $topsites_php_url to the url to the directory you're installing Aardvark Topsites PHP in.