You should be able to buy a kit that lets you convert the soldered version to the new type with the connector. You don't want to cut the existing wires, desolder them from the bad switch and solder new ends onto it. These ends fit into a new connector (part of the kit) and this plugs into the new switch.
I did this on my 83 SD. Not cheap at 75 for the kit and 110 for the switch, but I don't think you can buy the old type switch anymore except used... I guess if you can find a working one you could transfer the wires over. I would still rather desolder the old wires rather than cut and splice...Oh and be very careful that you don't break the newly installed switch when you go to reinstall the door skin (don't ask me how I know this...)
just my 0.02

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Bob Roe
Lehigh Valley PA USA
1973 Olds 88, 1972 MB 280SE, 1978 Datsun 280Z, 1971 Ford T-Bird, 1972 Olds 88, 1983 Nissan Sentra, 1985 Sentra, 1973 230.6, 1990 Acura Integra, 1991 Volvo 940GLE wagon, 1983 300SD, 1984 300SD, 1995 Subaru Legacy L wagon, 2002 Mountaineer, 1991 300TE wagon, 2008 Murano, 2007 R320CDI 4Matic 52K, some Hyundai, 2008 BMW 535xi wagon, all gone... currently
2007 Honda Odyssey Touring, 2014 E350 4matic