I no longer need Dawnguard as a master file for my mod.

I read that some people can just go File > Data and click on the mod then on the right click on Dawnguard and press delete but this does not work at all with my creation kit (nothing happens).

I've also seen some people use fallout 3 tools but I dont own fallout 3 and it's not worth buying it purely to use 1 tool.

Anyone know how to remove some parent masters from a esp?

Hold down Ctrl and press Delete on the keyboard.

Dammit, people never once mentioned about Ctrl.

YOU CAN DO THAT!?
Oh my god, I wish I had known that a few weeks ago, grrr. I too was fooled by the blasted CTRL key.