I'd echo the statements from the other posters here-- outside assistance would help you tremendously and, honestly, what you've got is probably an afternoon's worth of work (based on having done a number of migrations that are similar).
Here's how I'd do this to maintain the old server name, file share structure, etc. (I think it's a great thing to preserve as much of the old structure as possible so that you don't have user confusion, broken shortcuts, etc.)
Install W2K8R2 onto the new server computer ("NEWSERVER") and configure it with OLDSERVER as its DNS server.
Promote NEWSERVER to a domain controller. Install the DNS service on NEWSERVER and configure it to use itself as its DNS server after Active Directory has completed replicating from OLDSERVER.
Reconfigure the OLDSERVER computer to use NEWSERVER as its DNS server. Demote OLDSERVER to being a member server computer. This will allow you to rename OLDSERVER to another name (call it OLDSERVER-X). Change IP address of OLDSERVER-X to a new free IP address.
Configure NEWSERVER with an alias name to answer for the OLDSERVER computer name per this article: How to Configure Windows Machine to Allow File Sharing with DNS Alias
At this point you have a new server computer that can answer for the name of the old server computer and the old server computer remains on the network with a different name. You could promote OLDSERVER-X back to being a domain controller if the hardware is stable enough to use as a secondary domain controller.
Backups of the existing server computer before you begin are critical, but this method leaves the original server computer in a nearly untouched state (just no longer a domain controller and with a different name). In fact, I'd caution you to remove the file shares from the old server computer as soon as possible after the migration so that users don't "find" it and start saving files to it (since it'll still be fully functional).
Migrating the file shares from OLDSERVER-X to NEWSERVER could be as easy as
ROBOCOPYing a few directories and making some shares. Migrating the printers is as easy as using the built-in printer migration functionality in W2K8R2. Your license management application, though, is very likely "node locked" to OLDSERVER-X and you'll probably have to contact AutoDesk to get the necessary codes to move it over to NEWSERVER. It's possible that the license service will keep working on OLDSERVER-X while you do all this since you're not changing out the NIC (which is typically used as a "key" for node-locked licensing services, in my experience).
Backup will be different in W2K8 R2. I'd recommend you look at using the built-in backup functionality of W2K8 R2 because it's really easy to do bare metal restores with it.
You may want to consider installing a hypervisor (Hyper-V, VMware ESXi, etc) onto the new server computer before you install the OS. That will allow you to move the OS instance to new hardware in the future w/o any concerns about hardware compatibility. I'm doing that nearly all the time now in situations like this where the small performance hit of virtualization doesn't make any difference in the end result.
If you weren't in Canada or I had a passport I'd offer to fly out and do this for you as a weekend project. >smile< It could almost all be done remotely actually.
Anybody who tells you that you can't preserve the old server name, the old file share structure, etc, either doesn't know what they're doing or is seeing you as a cash cow. Likewise, anybody who says this is going to take more than 10 - 15 hours is probably inept, too (unless there's substantially more to this than your post describes). What you've got is a run-of-the-mill small business migration.