Depends on the condition. Sometimes its totally dried out and cracking. That's when I'll basically chisel it out like mentioned above. If it's not as dried out, then I use heat.

68 Road Runner, 69 Belvedere, 71 Challenger Vert
340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z
66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram