I have a 3 year old Whirlpool oven that will not longer light on the bake or broil functions. After testing I have found the gas valve to be bad (no longer reads 216 ohms from common to bake terminals) and have ordered another off this site. Is the valve replacement pretty straightforward or are there some things I should know. I consider myself handy but gas apliances always make me a little nervous. also, do I need any thread sealer for the connections other than the main gas line? Any advice would be appreciated!