Okay, here is a basic how to with this. It's the best I can explain so if you need more help you may need to google it. Also, this assumes you have pico installed on your server, it usually is.
Access the server using
Putty or your favorite command line program.
Login as root
Type in:
cd /usr/local/lib to get to the proper directory
Now type in:
pico php.ini and it will open up php.ini
Do a
ctrl w to bring up the search
Type in
upload_max_filesize and hit enter, this will take you to the line you need to edit
Change the number "2" to whatever you want in MegaBytes
When you are done hit
ctrl x and hit the
y button to save the buffer.
That's it