hub dust cap removal

[rsmartin]

guys, i'm having a real hard time getting the hub cap off my 560SEL. with 93,000 miles, i think it's the first time it's been pulled off! my rotors are worn way below specs so i'm trying to replace them and do bearings etc.

any hints on best way to get it off? i've tried with my channel lock pliers but no go for me. i'm an accountant so not much of a grip.. maybe i'm too weak!!