Simple question regarding valve cover gasket
I'm about to change my valve cover gasket. Ive read a few DIYs, but none of them say anything about draining the oil. Based on pictures I've seen I'm assuming that it needs to be drained, but a friend of mine claims that he did his valve cover and didn't need to drain the oil. I was wondering if I have to drain the oil or if I only need to drain around 1 or 2 liters (because I recently changed the oil approximately 900k ago).
If anyone also has any other sugestions about making this DIY a little easier then feel free to post. I'm already going to use high temp sealant for the areas prone to leaking.