it can be done this way also, with just your PC
try this, pasted from wololo
I think The Z's method is way to hard for noobs..
I did not want to make a new topic for this as there's already one..
My Method..
1. Download and install "
PS3.ProxyServer.GUI"
http://www.ps3hax.net/downloads.php?do=file&id=92&act=down
2. Start PS3.ProxyServer.GUI and Type in your PC's IP then select "PSP Mode" and click Start..
3. Click the Logs Tab, Then on your Vita Go to WiFi Settings and enter your PC's IP for the Proxy.
4. Go to System Update and click "Update Using Wi-Fi".. It will show the Latest Version then click "Next" and "Yes" Then "
Do Not Accept" and "Yes".. This will give you the Link to the PUP file it will download and install..
5. Copy this link from the Logs screen and click "Replace File" Tab.. Past that link on the left side. On the Right side click the Little button and select the PUP file you want to install.
6. Now click the "Logs" Tab again and click "Update Using Wi-Fi" and make sure in the "Logs" Tab is says that the files has been Redirected to a local file.
7. Done you can update to any Version you want.. (
You can not downgrade this way)
heres the 3.18 official vita firmware,
http://www.filedropper.com/psvitaofw318complete