So i just got a new GPU and PSU and as a result had to get a new Case. It will be the first time ive ever taken a motherboard out of a case and put it into a new one. I want to know if i have to remove the CPU fan and heat sink. Or if i can leave it on while moving the mobo.
More aboutchanging cases
No. I recommend you leave them on.
You can just leave the heatsink on. If you take it off you will have to re-paste the CPU (may be worth doing if it has been more than say 6months since you last did it).