Replacing Climate Control Buttons

[SLeazy Rider]

I ordered several replacement buttons for the climate control system in my '87 560 SL (like the "off" button and "compressor" button). They have arrived, and now I need some simple advice regarding how to switch them out. Assume I know nothing about car repair/restoration (which is not far from the truth). How do I remove the old buttons and replace with the new? Do I need any special tools to remove the old buttons or can I just pull them out with my fingers? I don't want to apply undue pressure and mess something up.

Also, I will soon receive a new "automatic blower" button as well (the thin white button on the right hand side); it was on back-order. The original of that one is completely missing. Once I receive the replacement, will it just slide into the empty slot?

Finally, I ordered and received a replacement "fresh air knob," which controls the flow of air from the side vent (it's really not a knob at all, but the little black rectangle that is used to open or close the A/C-heat vent). Do I just glue it on and, if so, what type/brand of glue do you recommend?

Thanks in advance for any help.

Glenn (aka "SLeazy Rider")