I bought a cheap ham a few months back that came the same way. Like you, I got about 3/4 of it off before finally throwing it on the smoker. After about two hours I was able to remove the remaining amounts.
Funny thing, it turned out to be one of the best hams I've ever had.
(Insert new smoker here!), Weber WSM-22, Weber 26.75 OTG, Blue Weber Performer with gas assist, Pit Barrel Cooker, UDS with rotisserie, SJG mini-WSM, Weber Go Anywhere