Second step - the software. There are several packages that can connect to the database. While ARC396 from BuTel is pretty much the acknowledged champ (you can get that from Scanner Master), there are 2 freeware packages - FreeScan and BcTool - that can also do this. You can read up on those packages and more via links on this article
Each of the freeware packages have their own forums (BcTool uses Yahoo groups, where it stores the latest version of their software; FreeScan has their own forum area on their website) and their authors watch them pretty regularly for questions and how-tos.
Another source of information would be anyone here who could supply you with a Uniden Advanced System Director (UASD) file - that can be imported via software. You might also find that someone has already built something on the New Hampshire Scanner Yahoo group (very active group), or on the popular Scan Cape Cod website...
No need to download anything.
No need for any special software either. I've found I learn my way around a new scanner much faster by avoiding programming via software and program it manually from the keypad instead.
Do the following on the 396T:
1. Create a new system in the 396T.
2. Set the type of system to 800MHz Motorola Type II.
3. Set "control channel only" mode to ON.
4. Enter 868.4500 MHz as a channel in the system. This is the main control channel in the Nashua system.