how to install 3.80 1.50 kernel add-on ?

I tried installing it as mentioned on a post here but it is showing up as a corrupt file under games. I placed the 150.pbp in the root and the add on files under
/PSP/GAME/UPDATE. Someone has mentioned placing the add ons in /PSP/GAME/150addon instead of /PSP/GAME/UPDATE. Does this make sense and if so why?
thanks

I don't think you're suppose to use the 'UPDATE' folder. Just stick it in 'GAME'.
And you have a phat psp right?

This should help.

Instructions

* Copy the files in the release to a directory called anything BUT UPDATE
* Move the UPDATE directory to /PSP/GAME/.
* Get sony 1.50 update and copy it to the root with name "150.PBP"
* Run the program and done.