I have started the main quest and I wanted to kill Helseth right off the bat so I can take

his ring. I've already killed all of the guards including Karrod, who I looted for his "odd

dwemer weapon" and I have pickpocked Helseth for his sword while he is standing around

doing nothing. If I kill him now at the start of the main quest can I finish the whole quest

with Fedris Hler, or do I have to start the main quest over?