My motherboard was causing problems for my computer so I needed to get a new one which means that I need to take off my CPU cooler. I also ordered some new thermal paste I just don't know what is the proper way to remove thermal paste from a CPU.
solid and cured paste: scrape it off with a plastic straight edge, then use alcohol (isopropanol) and a lint free cloth (I use coffee filters) to remove any reside on the CPU and/or the cooler.
fresh liquidy paste: lint free cloth and alcohol. remove as much as you can and use a dampened cloth to remove residue. allow to dry
as always when working with components take grounding precautions.
Canned Grounding Rant-
shut down system and remove side panel. with the power cable plugged into the PSU touch a bare unpainted metal area of the case. (my favorite spot is an unpainted screw securing the PSU) once you have grounded yourself you can unplug the computers power cable from the PSU and can touch the system.
if you move your feet, or shuffle in your chair, plug in the cord, reground yourself and unplug again.
end canned rant-
when using rubbing alcohol, be sure to give it up to 2 hours to air dry before doing anything regarding applying new paste.
If reusing the same cooler, be sure to clean the cooler as well. as for grounding yourself, you can do what R_1 says, but you can also perform maintenance on your system using a dining room table where there is no carpet on the ground and a wooden chair or something to remove potential static buildup on your person and on things around you.