just take the extra time to remove the fuse... if something goes wrong you will kick yourself in the *** for a while because you didnt want to take 5 extra mins to take the fuse out
dont cross power and ground. Dont touch screw driver or tool used to remove the connector for power to the amp or else it will arc. Best is to take out fuse or be REALLY careful
just disconnect the negative terminal on the battery its easy as pie. If you try to pull the power or ground out of the amp or put it in while theres still power running through them your going to see some big sparks (as i learned the hard way,I blew my deck faceplate this way)