How to remove vacumn switch off the transfer case

How do I remove the vacumn switch from the transfer case on an 1989 XJ . How much for an replacement?

It unscrews, under the speedo cable output on the left rear of the transfer. It´s not listed in any of my manuals, dealer only, don´t know the price?
If your checking it, the port between the two index pins (12 oclock whatever position the switch is) is constant vacuum (goes through a CHECK valve) before reaching the switch. The 9 0clock (next port to left) is 2 wheel drive. The 6 Oclock (opposite the in port) is a vent. The 3 Oclock (or one port to the right of the in port) is 4X. The 4X, also operates the indicator light switch, on the shift motor. A short piece of tubing and the good old suck test, may help troubleshooting.
The steel threads on the switch may have frozen to the aluminum threads in the transfer. A good tight wrench and taping the end of the wrench with a plastic hammer, may help unfreeze the threads. Something your gonna have to do with feeling, I´d take my time and try not to force it with excessive pressure, short jerks often works better, helps break the bond, hopefully without snapping off the threads.
Spraying a little WD-40 into the ports, on the switch, may help free it up, (the piston in the switch), worth a try.

thanks will try to spray it first before I take it out its stuck in 4wd mode ie pulling vacumn all the time on the 4wd port

When I bought one a few years ago at a dealer it was only something like 16 bucks.

Be careful when reinstalling. It may not turn in the same amount as the original, and you may have trouble twisting the harness to fit it back on. I came dangerously close to stripping mine out trying to line it up (actually I may have, but it never let go), so take it easy. Better to damage the tubing than trash the TC housing.

they really arent too tight. since there isnt much room it can be removed by gripping it with vise grips or even pliers. just remember to check for an o-ring on the new sensor or it will seap.