Locked PSN account? Can he access the XMB menu? If so then he should be able to copy most of his saves to a USB stick for example and then transfer them where-ever (there are a few exceptions to this though as some games have locked saves that cannot be copied). If this fails to work then you can do the following:
Download Kmeaw's custom firmware file, make sure you are on 3.55 official firmware first then follow the instruction below (snipped from another post of mine):
Put the PUP file (should be named to PS3UPDAT.PUP) inside X:/PS3/UPDATE/, where X: is the USB stick/device letter and plug it into the PS3, then update via the 'Update from removable storage media' option from the XMB (may not be that exact phrasing).
You can then proced to download blackb0x FTP server v1.2 (latest) and install it, it will come as a .pkg file which you can install via 'Install Package Files' on the game XMB, you can load it up, then connect to your PS3 either remotely or via ethernet cable (no crossover cables required!) using software such as flashfxp or filezilla, I prefer the former as the latter option tends to have a few problems with blackb0x. Then you can ftp into the PS3 using the IP provided with blackb0x and access the saves and transfer them to your PC.