I don't have a charge 4 so I'm only going off the internet here, but you can follow some of the steps here to replace the battery https://www.youtube.com/watch?v=2C1DiVXj... and if you need any further guidance please let me know

No problem anything to make the world a more fixable place

Thank you much. I just wanted to replace the thermal paste that stuff was crusty. This machine is older than me and running Linux just fine.