How to Replace a Heater Core and Coolant on a Mk7 Golf \ GTI \ R

This is how I replaced the heater core and changed the coolant on my 2015 Mk7 GTI. This was the first time I replaced a heater core and the first time making a vid like this. So post any tips if you got them. If you have any questions, put them in the comments and I'll try my best to answer them.