Download and install WinRAR:
http://www.rarlab.com/rar/wrar500.exe

Download iTools: 

http://itools.cn/multi_lang_pc_download.htm 

Then download the BBM ipa file: 

http://qzal.net/01/2013-08/6cfd2d57601.zip 

Plug in your iPhone 

Now open iTools, go to your apps on your phone and click install (top right) 
select the BBM ipa file you just downloaded. 

When you open the app it will ask for apple id etc... 

use : username - L777n@live.nl 
password - Ss123456 (case sensitive)