currently have front door separates power by headunit. contemplating on diy install of amplifier and subwoofer.

can anyone give step by step install procedure?

did some reading on the net but not sure... bale hindi na gagamitin yon stock speaker wire to front door and kailangan put new wire from amp to crossover?

how hard is it to snake speaker wire thru the rubber grommet of front door?

everytime mag on ng radio naka on rin amp?