Do I have to disconnect the battery and should i worry that my key fob wont work afterwards?

 

Cleaning WHAT connector contact?

Your fob will work after you reconnect your battery.

 

sorry i want to clean the connectors of my coils and of the crank sensor
also if I put in a grounding kit do I disconnect the battery?
Which side positive or negative?

 

You shouldn't need to clean the contacts of either of those parts.

GROUNDING kit = GROUND = negative.

If you don't understand the dynamics of disconnecting a battery terminal, I advise you consult a professional before causing irreversible damage.