If you have 6.35 your only option for now is using HEN:
HEN for 6.31 / 6.35 Installation
Download and unzip the appropriate HEN version for your PSP firmware below
Download and unzip Half Byte Loader R112 for Minna no Sukkiri
Copy the “hbl” directory and the “h.bin” file to the root of your device
Download and unzip the Minna no Sukkiri PSP Demo
Unzip UCJS10094.zip (the SAVEDATA exploit) and copy to PSP/SAVEDATA
Replace HBL’s “hbl/menu/EBOOT.PBP” with the appropriate HEN version
Start up Minna no Sukkiri and enjoy!
This was took from PSP-hacks. You could google it...
PlayStation 2 [SCPH-30004 R]: Free McBoot 1.8c + Network Adaptor 80GB HDD
PSP 2004: TA-085v2