I found this on a website.... I am unsure if this will work or not since I dont have a NEO 4..... Give it a try......
How to do the DVDR swap
Turn on the PS2 with no disc
Press X to go into the browser screen
Press eject and put in your original DVD game (Big TOC)
Press eject again and hold till gold disc comes on screen
Let go and tray will eject slowly- swap with your DVDR backup
Press X and play - its that simple
Note the best boot disc to use at the time of this post is GTA3 4.37GB
How to do the EA Swap
Turn on the PS2 with no disc
Press X to go into the browser screen
Press eject and put in your original PS2 CD based disc
Press eject again and hold till blue disc comes on screen
Let go and tray will eject - swap with your EA non patched game
Press X and play - its that simple
Note the best boot disc can be ANY PS2 CD Based disc - even magazine coverdiscs will work