Note:
ms0: is the root folder of the psp.
Download these:
Half byte loader and
TN-B link 1 or
TN-B link 2.
Hook up your psp with usb cable, on computer:
Run the half byte loader installer.
Run the TN-B installer. (one of them selects your psp drive automatically)
On Psp:
Goto Game -> memory stick, run the patapon demo 2, load the save game and once it loads hit the R button.
This should load the HBL, once it's loaded you will have a menu with "hen" on it, run hen.
It should now look like you have restarted the psp but now it is running 6.20 TN-B firmware until you switch the psp off.
Adding iso loader:
Download either
Prometheus or
OpenIdea.
Prometheus:
Extract it to the psp in ms0:/PSP/GAME/.
You need to run Prometheus from the "Game -> Memory Stick".
Any iso's within the "ms0:/PSP/GAME/ISO" folder will show up on the Prometheus menu.
OpenIdea:
Extract it to the psp drive.
Add "ms0:/PSP/SYSTEM/OIP/isoctrl.prx 1" to "ms0:/SEPLUGINS/vsh.txt".
Any iso's within the "ms0:/PSP/GAME/ISO" folder will show up under the Game -> Memory Stick on the psp.