Ignition Switch

I just had the alternator replaced about 9 months ago in my '98 900S convertible with manual transmission. It was obvious due to the light on the dash warning of the problem. My car is now dying with all of the indicator gauges going to zero as if the car was being turned off at the ignition switch. Since my first posting I have been getting the car to continue running by spraying WD40 directly into the key slot of the ignition switch to facilitate cleaning the contacts. It is temporary, however it has worked for three or four months. If anyone knows how to get the old switch out and new one in, I would certainly appreciate the advice. Thank you. Scott