Connect IVR to OutBound Call

I am new to asterisk and want to create an IVR application that is executed on an out going call.
For example : I want the asterisk to call people using their phone numbers from my database and on successful connection with these people i want to play my IVR application.

Now the issue I am facing is that i have created the IVR application and i know how to place and outgoing call using *.call files. The *.call files once loaded can not be unloaded so later when I want to remove that call file and add new one I don’t know how to go about it?

If this way of approach is wrong or inefficient can you guys suggest any other way?

PS- I am creating *.call files from my database using bash script(sort of automation).