Open PHPmyAdmin, find the database and select it. Once you have selected it by clicking it's name in the left side toolbar of myAdmin it will bring up the db tables. Click on Export from the top toolbar. You can either select Quick, or Custom. If you choose quick, just click the Go button. If you choose Custom, you'll need to click the Select All, or manually select all rows by clicking on the top one and scroll to the bottom, hold down Shift and click the very bottom row. They should all be highlighted blue if selected. Now click Export.
You'll now choose where to save the SQL file. When it finishes downloading, find the file and open it in a text editor like Notepad++. Click to insert the cursor in the top of the file and hold down Ctrl+F to bring up the find panel. Now click on the replace tab. Type in http://www.avrdev.net, and in the Replace dialogue Type the new URL prefix to replace the old. What you've done is replace all instances of old URL with the new. Now save the SQL file and go back to PHPmyAdmin.
You should make sure you have the original SQL file just in case, so if you saved over the one you downloaded earlier, repeat the first step and download the DB by exporting it. Now you will click the db to select it in PHPmyAdmin. CLick the checkbox on the bottom below the DB rows that says Check All. With them checked and selected, click With Selected>Delete. Now click on Import from the top row and navigate to the SQL file you altered to show the new path and upload it.