did you build the pc on your own? Probably someone 'did' apply paste if you purchased it from someone else, otherwise you would have had the heat issue a loooot sooner. It is fairly straightforward to apply and the paste costs like a dollar. It is however not without 'some' risk, its easy to find a youtube video to show you how to do it, if you still feel uncertain about the process a local IT store should be able to do it (although it might cost you) If heat IS the issue it is a good idea to atleast look at the layer of paste as it might be old, however, i dont advise looking before after you have had a look at the temperatures
