It shouldn’t be too difficult, depending on your particular setup, of course
Care to elaborate a little more? How many extensions, queues, ring groups, etc.
What phones are you using?
For example if they are from the 7900 line with SCCP protocol, you can go with chan-sccp-b to retain all functionality without the need to patch asterisk and install SCCP manager module for auto-provisioning so you don’t have to deal with the xml files. If they are from the newer 7800 line or the SPA line, they have SIP protocol and a web GUI for configuration too, you don’t need to deal with configuration files if you prefer to configure them manually.