To install, copy PSP directory from the Installer download below to your PSP. Place the 6.31 and 6.61 updates named 631.PBP and 661.PBP respectfully into the MAKER folder. Run the maker application.
If successful, there will be a DATA.MFC file in the MAKER folder. Copy this to the FLASHER folder and run the flasher. After this your device will reboot and you'll be in Infinity! From here, install any CFW you wish and activate the permament patch in the Infinity Configuration app.
Finally, here's a How to covering
6.60 plugins on 6.61, to quote:
I’ve been asked this question a lot and in most cases it would be very difficult to have a generic solution to a problem like this. Usually the difference between two firmware versions is significant enough that a plugin tied to particular version has to be manually updated by a developer in order to work on a newer firmware. Fortunately, 6.61 and 6.60 are so similar, I can release a plugin that will fake the version back to 6.60.
I’ve only tested it with a few plugins, but seems to work as intended. I am not sure if there is a lot of 6.61 plugins, but you need to make sure your seplugin text file is ordered in the following way:
Код
6.61 plugins
660_plugins_on_661.prx
6.60 plugins
The method used to patched the version is incredibly simplistic and could do with refining, but I’ll leave that to the eager reader. Source is in the package (linked above).