Oven would not keep the right temperature

I tried to take it out from the inside as the vidio shows. But it would not come out far enough. I pulled out the stove and removed back sheet metal panel. Unpluged the electric, Unhooked the temp sensor,pulled it out from the oven side. Put the new one through the hole,and rehooked it up. And got to clean up the dust and my missing oatmeal I spilled a while back. Turned it on. Checked it with a spare temp gage. Works so far.