'81 300SD How to replace vac switch on steering column lock

[tyl604]

http://www.peachparts.com/shopforum/attachments/diesel-discussion/141367d1489624526-81-300sd-hard-shut-down-ignition-switch-steering-wheel-lock-1-16.jpg

My SD will not shut down and I have traced the vac leak (thank you Mityvac) to the two nipple vac switch which is a part of the ignition switch and steering wheel locking mechanism. It is part #11 circled in the pic above.

How do I replace this part; do all the guts have to come out of the dash to replace just that one part? Not replacing the tumbler, elec switch, steering wheel lock - just the two nipple vac switch. For background see my thread called '81 300SD - Hard to shut down. Thanks to Alec300sd and Diseasel300 for all the help on that thread; their help got me to this point.