There are ways to add it, but it's fairly involved. A good chance of bricking if not done properly. Here you go, if you so desire (not originally posted by me, just passing on the info):
I think it should be possible, but there is a risk of causing device errors if it goes wrong.
If you are willing to experiment, with the knowledge you can roll back to the original Orange OS at any time, we can help.
First, install the original OS from Orange. This will have your language resource files in the form: net_rim_runtime_resource__he.cod
Use Window File Manager and navigate to c:\program files\common files\research in motion\shared\loader files\device OS\java
Copy all the resources that end in your language suffix and paste them into the update directory.
Then you will need a text editor to open BlackBerry.alx. Copy the following from the original to the update:
<!--Hebrew language description text -->
<name>יישומ&# x0 5d9; ליבה של BlackBerry %_appsVersion:V02%</name>
<description>יישו&#x 05 de;י ליבה של סידרת BlackBerry %series% </description>
Search for all occurrences of "Hebrew" and repeat the process.
Open each of the AXL files and repeat the process.
Save the changes.
Connect your device and start Applications Loader. One of two thing is likely to happen, your device may boot up correctly with the right language, or it might fail with an Uncaught Exception Error.
I finally found a very easy fix to my problem. I found and installed a allang. operating system. Decided on .86
mickrg123, 188.8.131.52 would be a VERY old version of the 9530's OS; I am not sure what carrier you are on but 184.108.40.206 is the latest Verizon official; and beyond that in the 4.7.0.x realm there exist .151 and .167
If you are not against trying leaked 5.0 OSes, I know that 220.127.116.11 has Portugese language support, unfortunately it doesn't appear that 18.104.22.168 does, so I am not sure the 22.214.171.124 leak/"hybrid" would either.
I would personally recommend trying 126.96.36.199 as I cannot for the life of me find a 188.8.131.52 installer that includes Portugese.
If you DO decide to try 184.108.40.206, you can get it from this thread:
Just remember to check "Add/Remove Programs" (XP) or "Programs and Features" (Vista/Win7) for "Blackberry Internal Tools for RIM" and uninstall THAT from your PC before loading the OS to your device, otherwise it will "phone home" to RIM with debug data periodically.