antenna replacement

[loansumrider]

I have an 05 Chevy Silverado pickup. On the last family outing a large bird hit the antenna and broke it off at the base. the question is how do I get under the dashboard to replace this part # 15829166. The antenna screws on to the base and has about 12 to 14 in long cable. the antenna cable is in sections. I need to disconnect the end piece for replacement. :deadhorse

thank you
Jim