before attempting any mods, always make a FULL backup of the phone first using Flash&Backup3. there are guides for Getting Connected and backing up in the guides section of this forum
its a v3r with STICKY D3R f/w. which means you should only flash MP's that start with R4515 and end with D3R.
if you wanna edit the GainTable to increase volume, do it after flashing the MP you want. anything done before flashing will be overwritten.