you can probably change your technique to get rid of most of this. However, once recorded you can do a low with some compression and EQ. It might be that there's too much transient attack which a compressor would help with. It might be that there's too much of a specific frequency band. Personally, I find that if there's too much "clack" you need to cut around 2KHz, where is there's too much "click" you need to cut nearer 4KHz.
My bassist has a weird technique where he's always slapping the strings against the fretboard really hard, and it creates this kind of "clacking" on every bloody note. A fairly thin notch at 2KHz seems to get rid.