Have you checked other things before replacing?
Possible causes of an inoperative blower motor include:
• Open fuse
• Inoperative blower motor resistor
• Inoperative blower motor switch
• Inoperative blower motor
• Inoperative blower motor circuit wiring or wire harness connectors
The 2008 Manual says that the blower is on passenger side under the interior cowl. If you do a search for Service Manual you may find what you are looking for, or at least it will give you an idea.
Hope it helps.
2012 DodgeRam 1500 4x4, 20% Tint, Running Boards, Class IV Hitch, 14" Win Muffler, Catch-Can, Tow-Hooks, LED Tailgate Bar
2008 Dodge Supe Bee, Catch Can, Backup Camera, 20% Tint all windows, CAI, AFE Filter