how to remove the black knobs to get the rear fender off?

[rnbrn21]

Can anyone tell me how the two black round knobs come off. I'm fixing my HST fan and am trying to get the fender off and those knobs don't want to budge and I don't want to break them.

 

[rnbrn21]

Never mind, I got them off. Just pull really hard, or in my case, carefully use a crowbar.

 

[moriboy]

Some of them have a little hole on top. Use an air gun and blow some air in. They come off easy!