Setup BGP

I need to setup BGP on our cisco 2901 router and it will need to failover to the backup circuit, which is in use now. I have a BSO circuit which connects to the Cisco 2901 and the remote end is advertising 172.21.221.0 and 172.19.221.0 networks and we are advertising our internal network 192.168.150.0 . Originally i have been using HSRP to switch between our primary and backup circuits, but since the circuit was changed on our Primary router ( Cisco 2901) i can't get any connectivity via BGP, but i am connecting to the remote router. I believe it to be a straight forward setup for an experienced technician. If a config is required then please let me know.