I bought arctic silver for my cpu's heatsink and fan and i'm wondering how I use it properly. I just don't want to put too much on cause than it will become less efficient.

Also, what should i use to get the stock thermal compound on the cpu and heatsink off?

To your second question...

I just wiped mine off with a sheet of paper. I'm sure there's a better, possibly safer way to do it, though

Here you've got instructions.