Download BBM for lower versions of android @ http://www.4shared.com/mobile/VkuLvY1Jce...out_ro.htm . if that doesnt work then use the method below.
1. Download d 2 files given below and you must install titanium backup
2. Install bbmgbarmv6.apk and don't open it
3. Now download the backup files named bbm-on-gb-tb-teztazsirama below
4. Extract all and put the content inside titanium backup folder
5. Open titanium backup and restore BBM Data only
6. After restore complete, now return
to your BBM and open it.