Vacuum lines have transmission fluid in them?

Since I haven't had heat on the floor, I found out the vacuum lines have transmission fluid in them. I am going to replace the 4-wheel drive indicator switch on the side of the transmission and the 4wd front vacuum actuator which is not working. The question is, should I blow air in all the lines with compressed air and then replace with new silicone lines? When I do this, will the compressed air blow any lines inside the dash that will make more of a headache for me to uncover and cause more of a problem? My main concern is getting the heat to the floor and not the vents and getting my vehicle working again before the next snow fall. It does go in gear but won't engage. I just need your thoughts on what would be the better way and easiest way to go about these issues. Thanks for any info on this and God bless on the work you do.