This boss fight against Wilhelm for me was quite easy. I didn't use any fancy tactics cause i don't know any. I am just level 17 experience but there was one reason i could defeat him so easily. I used a really good shotgun to first destroy the repair surveyors and every time Wilhelm tried to spawn new ones i blasted those with my shotgun. Really, if you just keep shooting Wilhelm with a high damage gun, he doesn't stand a chance. Oh and by the way remember to stock up on ammo.

This boss fight against Wilhelm for me was quite easy. I didn't use any fancy tactics cause I don't know any. 

I am just at level 17 but there was one reason I could defeat him so easily: I used a really good shotgun to first destroy the repair surveyors and every time Wilhelm tried to spawn new ones I blasted those with my shotgun. Really, if you just keep shooting Wilhelm with a high damage gun, he doesn't stand a chance. Oh and by the way remember to stock up on ammo.