Hello and welcome to the AT Forums, Stantonk.
I'm very surprised that your temps are as low as they are! The two ARE NOT supposed to be used together. Ever. :Q
One or the other. At this point, the thermal pad has already been heated up (there's a technical word that I can't think of...) so, if you remove the HS the pad is garbage anyway.
Remove the HS. With your fingernail, scrape off all the pink stuff (thermal pad) Whatever won't come off will come off using a papertowel w/rubbing alcohol on it.
Clean the CPU slug (that's the part with the writing on it) until there's no trace of thermal pad/Arctic Silver on it. Rubbing alcohol is OK here too.
Then, put a thin layer (almost, but not quite see-thru) of AS on the CPU slug. Remount HS. You are done.
Ask more questions if you need to. 🙂 Good luck.