Press the lower part of thing on left side of scanner that looks sort of like a push to talk button
You should see menu
Turn the right knob on top the scanner to "see scanner info" and press E
Scroll to Firmware version version,hopefully you have 2.60.00
If not you will have to go here
BC246TFirmwareUpdate < UnidenMan4 < TWiki
and download the update to send to your scanner.
You will need the cable that cane with the scanner.
After sending the firmware update to the scanner you need to program in Band Plan 1 & Band Plan 2
Go here for info on programing Band Plans
Easier to Read BC246T Scanner Manual
Scroll down to
Edit Band Plan (Custom/VHF/UHF Motorola systems only)For Custom (rebanded) Motorola Systems.
Do Bandplan 1 first then go back and do Band Plan 2
Hope that help you
BC246T - The RadioReference Wiki