Trophy hunter

[phosphilia]

HELP!
ive been stuck on the a hunter quest for about a week now, i know you need charged creepers but somehow i never get them. when i do though, i always fail and end up dying, ive died 12 times already.
does anyone have any tips on how to get the heads?

 

[TexasTuberTimYT]

I haven't done that quest yet but heard you can put the creeper spawner with other mobs and then use flint and steel.