I have not been wiping the stove top after cooking for several years. Last month I tried to clean it by taking some baking soda + water and scrubbing with steel wool. I did manage to get a lot of the dirt off but it is not clean enough. Any suggestions about how I can remove the grease off the stove top?   
Automatic dishwasher detergent.  The gel type like Cascade (in US) is good for this.  It is thick so it will stay where you put it.  The active ingredient is sodium carbonate which saponifies fats and makes them easy to wipe off. It does not stink like ammonia.  It will not scratch the enamel.  Plus you might already have some.  Put some dishwasher gel on the grease and leave it overnight.  In the morning you will be able to wipe the gel and grease off.   