[SOLVED] How to install broadcom WLAN driver on LiveUSB?

Hello.. :)
A complete, absolute beginner to Linux here.
I tried to install Xubuntu 12.04 on laptop, but unfortunately it failed.. miserably if i may add.. So I am currently using the LiveUSB for working on it.
Laptop Specifications:
compaq presario 2500
WLAN driver: BCM4306 rev 02
Ram: 512, but some part is allocated for graphics i think

Oh and also, this is a very very old laptop.

I just want to know how to install the firmware for the wlan card. is it possible to do it on liveUSB? I dont want to get into reinstalling xubuntu right now.
any help at all would be appreciated
if any more information is needed please do tell me..