Is this what I need?You can cut the connector off the wiring harness and put spade connectors on the wires or, what most of us do, get Metra adapters so we don't have to cut anything.
I only have the base audio system and I know that the dash speakers are a different adapter from the door speakers. Crutchfield will identify the ones you need. You can either get them from there (I think at some price point they include them for free) or you can take that part number and search for a better price (e.g. Amazon).
IMO you don't gain anything by removing the adapter on the OEM wiring. So much easier to just get the adapter and use that.
Crutchfield shows Metra 72-7902 for the dash and 72-6515 for the doors.