Need to downgrade and haven't a clue how to, well you came to the right place. Everything you need is in the download.
If you have a TA-082 Model (Check Here) It can now be Downgraded make sure to download the right package 2.80->1.5.
Also them "Easy Downgraders" are OLD and UNSAFE, use the ones i have linked, they are the most up to date and your best option, any problems just post and i will try my best to help you.
The 2.71 Downgrader's Uses Dark_Alex's new Update Flasher for 2.71. Which is Extremely Safe. Also these downgrader's use official sony updates, so no need to do a clean install afterwards.
Upgrading to 2.71 and then downgrading from there to version 1.5, is the safest way of downgrading.
All downloads are with Installer's and Instruction's.
And i have personally tested each one myself for safety.
3.03 -->1.50
GTA unpatched version is needed.
Warning you cannot upgrade back to 3.03 for now
as if will harm your psp, it is ok for you to upgrade to 3.03oe.
2.80->1.50
Improved Version, works on motherboards TA-079->TA-086
2.71->1.50
Do Not Use On A TA-082->TA-086, Use 2.8 Downgrader
2.50/2.60->1.50
1.50->1.00
(risky and pointless)
----------------------------------------------------------------------------------------- What To Do After DownGrading
3.10oe-A Open Edition Firmware Installer If you have a 1.5, you can use this, Its 3.10 mixed with 1.5 so you can play your PSX games without the need for a PS3 and all the other features 3.10 has, It other best strength it it can launch homebrew just like a 1.5 and also launch ISO's straight from the GAME menu.
Devhook for 2.71(esp. TA-082) If you have a TA-082 Model PSP or v2.71 and if you are afraid of downgrading, you can still use devhook and use ISo's aswell and not miss out on anything a 1.5 has. (To Do So Check Here)
Devhook .51.1 Installer When you have downgraded to 1.5, you will need Devhook to play your Umd's and ISO's(but i advise on getting 3.03oe).
Here's a Link, to Devhook .51.1 Installer
Devhook for 1.5 Maxed out When you have downgraded to 1.5, you will need Devhook to play your Umd's and ISO's.
Here's a Link, to my personal Devhook.46.