Upgrading from Pixelpost 1.7.3
Phosho will use your existing Pixelpost database, and retain your connection details.
Please make a backup of your Pixelpost installation before attempting an upgrade to PhoSho - just in case! Also, make sure that the includes folder (where the pixelpost.php file is) is writable.
Download the files for PhoSho, and upload them to your web server, just as you would with Pixelpost. The first time you log in as admin the upgrade will happen behind the scenes. The best way to check that the upgrade has worked is to go to the options page and set the parameters to resize the image on upload. If it saves the parameters without errors, then the upgrade worked.
The upgrade process looks for the pixelpost.php file, which is where the database connection information is stored. If it finds this file, it assumes you still have Pixelpost 1.7.3 installed. It adds a few fields to the config table, to handle picture resizing. It clears down the version table and replaces it with a new entry saying version 1. Finally it writes out phosho.php and deletes pixelpost.php.
Pixelpost 1.7.3 has been out for a long time, so I'm going to assume that everyone who has it will be on that version. Unfortunately I cannot provide support for upgrades from earlier versions of Pixelpost.