Reinstall A2billing / Asterisk

I have a running A2billing / Asterisk service on a Dedicated server , and now we are facing some problems ... Here are what i need: - backup the current a2billing database , everything except the A2billing configuration since we may have some problems in it. - After that we will format the server installing fresh CentOS on it. - Installing A2Billing/Asterisk with the latest stable versions and restoring the backup. - Secure the service by changing the default passwards and insure the system security against hacking. - doing small customizations / configurations for A2billing ( IVR for voucher refill / customer balance , activate CID forwarding for the clients , add some service ports other than default VOIP ports ...)