[xeroinfinity]

Welcome to AF.

I'm not real familiar with the Achieva, but I think we can figure it out.

You will probly need to remove the side pillar covers and the top of the back seat may need removed to acess some more retainer clips or screws.

You want to remove the whole thing, or just the speakers?
Because you should be able to get the grills off without removing the back dash panel.
Migth take some prying around the factory grills to get them up. I know they do have plastic clips built onto the grill check underneath for those and see if that'll get'em out.

Hope that helps.