I have a 1.5F engine with a valve cover I've been trying to remove, but I'm having a lot of difficulty. I removed the 4 bolts on top and I was able to get underneath it in all of the areas I could reach gently using a box cutter and putty knives. I'm not sure if the valve cover has ever been changed before, but it seemed to have a significant leak when I got it, which is why I wanted to replace the gasket. Now I'm at a place of no return with the amount of gasket I've cut into. Any suggestions on what to try next? It won't even nudge a little bit yet. Am I missing another bolt somewhere?