Is there a legit way to change diablo 2 language without having to dl the client from battle.net, some sort of patch or something?

Contact the "Blizzard" tech support and ask them your question for further help or post in the forum that I have posted as a link here for more in depth help from people:

http://forums.d2jsp.org/forum.php?f=21

Good luck.

To change the ingame text to another language, you would need to get the desired lang.dll. However, just googling for it and taking any download can be risky (viruses, malware). I suggest you to download the client, it won't take much longer than some hours.

i did this, but it didnt work, i got the d2lang.dll from a friend of mine who has english d2.

The only way I know of that this can/has been done is through Blizzards site

U have to uninstall D2, register ur CD key on bnet's site & download the desired language version from them