2001 windstar side speaker problem

intermittent problem with speaker in drivers side sliding door. how do i remove the side door panel, or is there another way to further diagnose whether it is a wiring, speaker or stereo problem? sorry for raising small issues... i searched the forum but couldn't find any info.

intermittent problem with speaker in drivers side sliding door. how do i remove the side door panel, or is there another way to further diagnose whether it is a wiring, speaker or stereo problem? sorry for raising small issues... i searched the forum but couldn't find any info.

Before removing the door panel, clean very well the contact (4) on the pillar, and also the 4 contacts on the door; 2 of these are the speaker contact and usually the problem comes from these contacts.

Thanx for the suggestion... cleaned the contacts well, and the problem has been resolved:)